| NTRS Link | 20160010115 |
| Title: | FUN3D Analyses in Support of the Second Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160010115 |
| Author: | Chwalowski, Pawel and Heeg, Jennifer |
| NASA Center: | Langley Research Center |
| Publication Date: | June 13, 2016 |
| Document ID: | 20160010115 |
| Report/Patent Number: | AIAA Paper 2016-3122, NF1676L-22812 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents the computational aeroelastic results generated in support of the second Aeroelastic Prediction Workshop for the Benchmark Supercritical Wing (BSCW) configurations and compares them to the experimental data. The computational results are obtained using FUN3D, an unstructured grid Reynolds- Averaged Navier-Stokes solver developed at NASA Langley Research Center. The analysis results include aerodynamic coefficients and surface pressures obtained for steady-state, static aeroelastic equilibrium, and unsteady flow due to a pitching wing or flutter prediction. Frequency response functions of the pressure coefficients with respect to the angular displacement are computed and compared with the experimental data. The effects of spatial and temporal convergence on the computational results are examined. |
| Meeting Information: | 16th AIAA Aviation Technology, Integration, and Operations Conference (Aviation 2016); June 13, 2016 - June 17, 2016; Washington, DC; United States
2nd AIAA Aeroelastic Prediction Workshop (AePW-2); January 02, 2016 - January 03, 2016; San Diego, CA; United States
AIAA Science and Technology Forum and Exposition (SciTech 2016); January 04, 2016 - January 08, 2016; San Diego, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | August 10, 2016 |
|
| NTRS Link | 20160010117 |
| Title: | Data Comparisons and Summary of the Second Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160010117 |
| Author: | Heeg, Jennifer and Wieseman, Carol D. and Chwalowski, Pawel |
| NASA Center: | Langley Research Center |
| Publication Date: | June 13, 2016 |
| Document ID: | 20160010117 |
| Report/Patent Number: | NF1676L-22809 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents the computational results generated by participating teams of the second Aeroelastic Prediction Workshop and compare them with experimental data. Aeroelastic and rigid configurations of the Benchmark Supercritical Wing (BSCW) wind tunnel model served as the focus for the workshop. The comparison data sets include unforced ("steady") system responses, forced pitch oscillations and coupled fluid-structure responses. Integrated coefficients, frequency response functions, and flutter onset conditions are compared. The flow conditions studied were in the transonic range, including both attached and separated flow conditions. Some of the technical discussions that took place at the workshop are summarized. |
| Meeting Information: | AIAA Aviation 2016; June 13, 2016 - June 17, 2016; Washington, DC; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | August 10, 2016 |
|
| NTRS Link | 20160007042 |
| Title: | Progress & Plans for the 2nd Aeroelastic Prediction Workshop (AePW-2) |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160007042 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Raveh, Daniella and Jirasek, Adam and Dalenbring, Mats and Scotti, Alessandro |
| NASA Center: | Langley Research Center |
| Publication Date: | April 16, 2016 |
| Document ID: | 20160007042 |
| Report/Patent Number: | NF1676L-21171 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Oral/Visual Presentation |
| Abstract: | No abstract available |
| Meeting Information: | Aerospace Flutter and Dynamics Council Meeting; April 16, 2015 - April 17, 2015; Moffett Field, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | June 07, 2016 |
|
| NTRS Link | 20160007038 |
| Title: | Progress and Plans for the 2nd Aeroelastic Prediction Workshop (AePW-2) |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160007038 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Raveh, Daniella and Jirasek, Adam and Dalenbring, Mats and Scotti, Alessandro |
| NASA Center: | Ames Research Center; Langley Research Center |
| Publication Date: | April 14, 2015 |
| Document ID: | 20160007038 |
| Report/Patent Number: | NF1676L-21189 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Oral/Visual Presentation |
| Abstract: | No abstract available |
| Meeting Information: | ASE Summit; April 14, 2015 - April 15, 2015; Moffett Field, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | June 06, 2016 |
|
| NTRS Link | 20160006927 |
| Title: | 2nd AIAA Aeroelastic Prediction Workshop: Plans & an Interesting Technical Issue |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160006927 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Schuster, David and Raveh, Daniella and Jirasek, Adam and Dalenbring, Mats |
| NASA Center: | Langley Research Center |
| Publication Date: | January 05, 2015 |
| Document ID: | 20160006927 |
| Report/Patent Number: | NF1676L-20567 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Oral/Visual Presentation |
| Abstract: | No abstract available |
| Meeting Information: | Aerodynamics Technical Working Group Meeting; January 05, 2015 - January 09, 2015; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | June 02, 2016 |
|
| NTRS Link | 20150006027 |
| Title: | Plans and Example Results for the 2nd AIAA Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20150006027 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Schuster, David M. and Raveh, Daniella and Jirasek, Adam and Dalenbring, Mats |
| NASA Center: | Langley Research Center |
| Publication Date: | January 05, 2015 |
| Document ID: | 20150006027 |
| Report/Patent Number: | NF1676L-18959 |
| Contract/Grant/Task Num: | WBS 794072.02.07.02.01 |
| Document Type: | Conference Paper |
| Abstract: | This paper summarizes the plans for the second AIAA Aeroelastic Prediction Workshop. The workshop is designed to assess the state-of-the-art of computational methods for predicting unsteady flow fields and aeroelastic response. The goals are to provide an impartial forum to evaluate the effectiveness of existing computer codes and modeling techniques, and to identify computational and experimental areas needing additional research and development. This paper provides guidelines and instructions for participants including the computational aerodynamic model, the structural dynamic properties, the experimental comparison data and the expected output data from simulations. The Benchmark Supercritical Wing (BSCW) has been chosen as the configuration for this workshop. The analyses to be performed will include aeroelastic flutter solutions of the wing mounted on a pitch-and-plunge apparatus. |
| Meeting Information: | 2nd AIAA SciTech 2015; January 05, 2015 - January 09, 2015; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | April 22, 2015 |
|
| NTRS Link | 20140007352 |
| Title: | Unsteady Aerodynamic Validation Experiences From the Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140007352 |
| Author: | Heeg, Jennifer and Chawlowski, Pawel |
| NASA Center: | Langley Research Center |
| Publication Date: | January 13, 2014 |
| Document ID: | 20140007352 |
| Report/Patent Number: | AIAA Paper 2014-0203, NF1676L-16688 |
| Contract/Grant/Task Num: | WBS 473452.02.07.04.02.03 |
| Document Type: | Conference Paper |
| Abstract: | The AIAA Aeroelastic Prediction Workshop (AePW) was held in April 2012, bringing together communities of aeroelasticians, computational fluid dynamicists and experimentalists. The extended objective was to assess the state of the art in computational aeroelastic methods as practical tools for the prediction of static and dynamic aeroelastic phenomena. As a step in this process, workshop participants analyzed unsteady aerodynamic and weakly-coupled aeroelastic cases. Forced oscillation and unforced system experiments and computations have been compared for three configurations. This paper emphasizes interpretation of the experimental data, computational results and their comparisons from the perspective of validation of unsteady system predictions. The issues examined in detail are variability introduced by input choices for the computations, post-processing, and static aeroelastic modeling. The final issue addressed is interpreting unsteady information that is present in experimental data that is assumed to be steady, and the resulting consequences on the comparison data sets. |
| Meeting Information: | 52nd AIAA Aerospace Sciences Meeting; January 13, 2014 - January 17, 2014; National Harbor, MD; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | July 09, 2014 |
|
| NTRS Link | 20130013395 |
| Title: | Overview of the Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130013395 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Schuster, David M. and Dalenbring, Mats |
| NASA Center: | Langley Research Center |
| Publication Date: | April 08, 2013 |
| Document ID: | 20130013395 |
| Report/Patent Number: | AIAA Paper 2013-1798, NF1676L-15301 |
| Contract/Grant/Task Num: | WBS 136905.02.04.04.16.05 |
| Document Type: | Conference Paper |
| Abstract: | The AIAA Aeroelastic Prediction Workshop (AePW) was held in April, 2012, bringing together communities of aeroelasticians and computational fluid dynamicists. The objective in conducting this workshop on aeroelastic prediction was to assess state-of-the-art computational aeroelasticity methods as practical tools for the prediction of static and dynamic aeroelastic phenomena. No comprehensive aeroelastic benchmarking validation standard currently exists, greatly hindering validation and state-of-the-art assessment objectives. The workshop was a step towards assessing the state of the art in computational aeroelasticity. This was an opportunity to discuss and evaluate the effectiveness of existing computer codes and modeling techniques for unsteady flow, and to identify computational and experimental areas needing additional research and development. Three configurations served as the basis for the workshop, providing different levels of geometric and flow field complexity. All cases considered involved supercritical airfoils at transonic conditions. The flow fields contained oscillating shocks and in some cases, regions of separation. The computational tools principally employed Reynolds-Averaged Navier Stokes solutions. The successes and failures of the computations and the experiments are examined in this paper. |
| Meeting Information: | 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference; April 08, 2013 - April 11, 2013; Boston, MA |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | May 10, 2013 |
|
| NTRS Link | 20130012907 |
| Title: | Structural Dynamics Modeling of HIRENASD in Support of the Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130012907 |
| Author: | Wieseman, Carol and Chwalowski, Pawel and Heeg, Jennifer and Boucke, Alexander and Castro, Jack |
| NASA Center: | Langley Research Center |
| Publication Date: | April 08, 2013 |
| Document ID: | 20130012907 |
| Report/Patent Number: | AIAA Paper 2013-1801, NF1676L-15290 |
| Contract/Grant/Task Num: | WBS 984754.02.07.07.20.06 |
| Document Type: | Conference Paper |
| Abstract: | An Aeroelastic Prediction Workshop (AePW) was held in April 2012 using three aeroelasticity case study wind tunnel tests for assessing the capabilities of various codes in making aeroelasticity predictions. One of these case studies was known as the HIRENASD model that was tested in the European Transonic Wind Tunnel (ETW). This paper summarizes the development of a standardized enhanced analytical HIRENASD structural model for use in the AePW effort. The modifications to the HIRENASD finite element model were validated by comparing modal frequencies, evaluating modal assurance criteria, comparing leading edge, trailing edge and twist of the wing with experiment and by performing steady and unsteady CFD analyses for one of the test conditions on the same grid, and identical processing of results. |
| Meeting Information: | 54th AIAA/ASME/ASCE/AHS/ASC, Structures, Structural Dynamics, and Materials Conference; Boston, MA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | April 25, 2013 |
|
| NTRS Link | 20130009660 |
| Title: | Analysis of Test Case Computations and Experiments for the First Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130009660 |
| Author: | Schuster, David M. and Heeg, Jennifer and Wieseman, Carol D. and Chwalowski, Pawel |
| NASA Center: | Langley Research Center |
| Publication Date: | January 07, 2013 |
| Document ID: | 20130009660 |
| Report/Patent Number: | AIAA Paper 2013-0788, NF1676L-15840 |
| Contract/Grant/Task Num: | WBS 869021.03.07.01.99 |
| Document Type: | Conference Paper |
| Abstract: | This paper compares computational and experimental data from the Aeroelastic Prediction Workshop (AePW) held in April 2012. This workshop was designed as a series of technical interchange meetings to assess the state of the art of computational methods for predicting unsteady flowfields and static and dynamic aeroelastic response. The goals are to provide an impartial forum to evaluate the effectiveness of existing computer codes and modeling techniques to simulate aeroelastic problems and to identify computational and experimental areas needing additional research and development. Three subject configurations were chosen from existing wind-tunnel data sets where there is pertinent experimental data available for comparison. Participant researchers analyzed one or more of the subject configurations, and results from all of these computations were compared at the workshop. |
| Meeting Information: | 51st AIAA Aerospace Sciences Meeting; January 07, 2013 - January 10, 2013; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | February 13, 2013 |
|
| NTRS Link | 20130003303 |
| Title: | Lessons Learned in the Selection and Development of Test Cases for the Aeroelastic Prediction Workshop: Rectangular Supercritical Wing |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130003303 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Wieseman, Carol D. and Florance, Jennifer P. and Schuster, David M. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 07, 2013 |
| Document ID: | 20130003303 |
| Report/Patent Number: | AIAA Paper 2013-0784, NF1676L-15813 |
| Contract/Grant/Task Num: | WBS 473452.02.07.04.02.03 |
| Document Type: | Conference Paper |
| Abstract: | The Aeroelastic Prediction Workshop brought together an international community of computational fluid dynamicists as a step in defining the state of the art in computational aeroelasticity. The Rectangular Supercritical Wing (RSW) was chosen as the first configuration to study due to its geometric simplicity, perceived simple flow field at transonic conditions and availability of an experimental data set containing forced oscillation response data. Six teams performed analyses of the RSW; they used Reynolds-Averaged Navier-Stokes flow solvers exercised assuming that the wing had a rigid structure. Both steady-state and forced oscillation computations were performed by each team. The results of these calculations were compared with each other and with the experimental data. The steady-state results from the computations capture many of the flow features of a classical supercritical airfoil pressure distribution. The most dominant feature of the oscillatory results is the upper surface shock dynamics. Substantial variations were observed among the computational solutions as well as differences relative to the experimental data. Contributing issues to these differences include substantial wind tunnel wall effects and diverse choices in the analysis parameters. |
| Meeting Information: | 51st AIAA Aerospace Sciences Meeting; January 07, 2013 - January 10, 2013; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | January 27, 2013 |
|
| NTRS Link | 20130003226 |
| Title: | FUN3D Analyses in Support of the First Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130003226 |
| Author: | Chwalowski, Pawel and Heeg, Jennifer and Wieseman, Carol D. and Florance, Jennifer P. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 07, 2013 |
| Document ID: | 20130003226 |
| Report/Patent Number: | AIAA Paper 2013-0785, NF1676L-14862 |
| Contract/Grant/Task Num: | WBS 984754.02.07.07.20.06 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents the computational aeroelastic results generated in support of the first Aeroelastic Prediction Workshop for the Benchmark Supercritical Wing (BSCW) and the HIgh REynolds Number AeroStructural Dynamics (HIRENASD) configurations and compares them to the experimental data. The computational results are obtained using FUN3D, an unstructured grid Reynolds-averaged Navier-Stokes solver developed at NASA Langley Research Center. The analysis results for both configurations include aerodynamic coefficients and surface pressures obtained for steady-state or static aeroelastic equilibrium (BSCW and HIRENASD, respectively) and for unsteady flow due to a pitching wing (BSCW) or modally-excited wing (HIRENASD). Frequency response functions of the pressure coefficients with respect to displacement are computed and compared with the experimental data. For the BSCW, the shock location is computed aft of the experimentally-located shock position. The pressure distribution upstream of this shock is in excellent agreement with the experimental data, but the pressure downstream of the shock in the separated flow region does not match as well. For HIRENASD, very good agreement between the numerical results and the experimental data is observed at the mid-span wing locations. |
| Meeting Information: | 51st AIAA Aerospace Sciences Meeting; January 07, 2013 - January 10, 2013; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | January 25, 2013 |
|
| NTRS Link | 20130003239 |
| Title: | Overview of the Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130003239 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel and Florance, Jennifer P. and Wieseman, Carol D. and Schuster, David M. and Perry, Raleigh B. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 07, 2013 |
| Document ID: | 20130003239 |
| Report/Patent Number: | NF1676L-15678, AIAA Paper 2013-0783 |
| Contract/Grant/Task Num: | WBS 473452.02.07.04.02.03 |
| Document Type: | Conference Paper |
| Abstract: | The Aeroelastic Prediction Workshop brought together an international community of computational fluid dynamicists as a step in defining the state of the art in computational aeroelasticity. This workshop's technical focus was prediction of unsteady pressure distributions resulting from forced motion, benchmarking the results first using unforced system data. The most challenging aspects of the physics were identified as capturing oscillatory shock behavior, dynamic shock-induced separated flow and tunnel wall boundary layer influences. The majority of the participants used unsteady Reynolds-averaged Navier Stokes codes. These codes were exercised at transonic Mach numbers for three configurations and comparisons were made with existing experimental data. Substantial variations were observed among the computational solutions as well as differences relative to the experimental data. Contributing issues to these differences include wall effects and wall modeling, non-standardized convergence criteria, inclusion of static aeroelastic deflection, methodology for oscillatory solutions, post-processing methods. Contributing issues pertaining principally to the experimental data sets include the position of the model relative to the tunnel wall, splitter plate size, wind tunnel expansion slot configuration, spacing and location of pressure instrumentation, and data processing methods. |
| Meeting Information: | 51st AIAA Aerospace Sciences Meeting; January 07, 2013 - January 10, 2013; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | January 25, 2013 |
|
| NTRS Link | 20120012006 |
| Title: | A Summary of Data and Findings from the First Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20120012006 |
| Author: | Schuster, David M. and Chwalowski, Pawel. and Heeg, Jennifer and Wieseman, Carol D. |
| NASA Center: | Langley Research Center |
| Publication Date: | July 09, 2012 |
| Document ID: | 20120012006 |
| Report/Patent Number: | NF1676L-13995 |
| Contract/Grant/Task Num: | WBS 869021.03.07.01.99 |
| Document Type: | Conference Paper |
| Abstract: | This paper summarizes data and findings from the first Aeroelastic Prediction Workshop (AePW) held in April, 2012. The workshop has been designed as a series of technical interchange meetings to assess the state of the art of computational methods for predicting unsteady flowfields and static and dynamic aeroelastic response. The goals are to provide an impartial forum to evaluate the effectiveness of existing computer codes and modeling techniques to simulate aeroelastic problems, and to identify computational and experimental areas needing additional research and development. For this initial workshop, three subject configurations have been chosen from existing wind tunnel data sets where there is pertinent experimental data available for comparison. Participant researchers analyzed one or more of the subject configurations and results from all of these computations were compared at the workshop. Keywords: Unsteady Aerodynamics, Aeroelasticity, Computational Fluid Dynamics, Transonic Flow, Separated Flow. |
| Meeting Information: | International Conference on Computational Fluid Dynamics; July 09, 2012 - July 13, 2012; Kohala Coast, HI; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | August 03, 2012 |
|
| NTRS Link | 20110015415 |
| Title: | Preliminary Computational Analysis of the (HIRENASD) Configuration in Preparation for the Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20110015415 |
| Author: | Chwalowski, Pawel and Florance, Jennifer P. and Heeg, Jennifer and Wieseman, Carol D. and Perry, Boyd P. |
| NASA Center: | Langley Research Center |
| Publication Date: | June 26, 2011 |
| Document ID: | 20110015415 |
| Report/Patent Number: | IFASD-2011-108, NF1676L-12739 |
| Contract/Grant/Task Num: | WBS 561581.02.08.07.20.16 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents preliminary computational aeroelastic analysis results generated in preparation for the first Aeroelastic Prediction Workshop (AePW). These results were produced using FUN3D software developed at NASA Langley and are compared against the experimental data generated during the HIgh REynolds Number Aero- Structural Dynamics (HIRENASD) Project. The HIRENASD wind-tunnel model was tested in the European Transonic Windtunnel in 2006 by Aachen University0s Department of Mechanics with funding from the German Research Foundation. The computational effort discussed here was performed (1) to obtain a preliminary assessment of the ability of the FUN3D code to accurately compute physical quantities experimentally measured on the HIRENASD model and (2) to translate the lessons learned from the FUN3D analysis of HIRENASD into a set of initial guidelines for the first AePW, which includes test cases for the HIRENASD model and its experimental data set. This paper compares the computational and experimental results obtained at Mach 0.8 for a Reynolds number of 7 million based on chord, corresponding to the HIRENASD test conditions No. 132 and No. 159. Aerodynamic loads and static aeroelastic displacements are compared at two levels of the grid resolution. Harmonic perturbation numerical results are compared with the experimental data using the magnitude and phase relationship between pressure coefficients and displacement. A dynamic aeroelastic numerical calculation is presented at one wind-tunnel condition in the form of the time history of the generalized displacements. Additional FUN3D validation results are also presented for the AGARD 445.6 wing data set. This wing was tested in the Transonic Dynamics Tunnel and is commonly used in the preliminary benchmarking of computational aeroelastic software. |
| Meeting Information: | International Forum on Aeroelasticity and Structural Dynamics; June 26, 2011 - June 30, 2011; Paris; France |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | September 19, 2011 |
|
| NTRS Link | 20110014269 |
| Title: | Plans for Aeroelastic Prediction Workshop |
| NTRS Full-Text: | http://hdl.handle.net/2060/20110014269 |
| Author: | Heeg, Jennifer and Ballmann, Josef and Bhatia, Kumar and Blades, Eric and Boucke, Alexander and Chwalowski, Pawel and Dietz, Guido and Dowell, Earl and Florance, Jennifer P. and Hansen, Thorsten and Mani, Mori and Marvriplis, Dimitri and Perry, Boyd, III and Ritter, Markus and Schuster, David M. and Smith, Marilyn and Taylor, Paul and Whiting, Brent and Wieseman, Carol C. |
| NASA Center: | Langley Research Center |
| Publication Date: | June 26, 2011 |
| Document ID: | 20110014269 |
| Report/Patent Number: | IFASD-2011-110, NF1676L-12724 |
| Contract/Grant/Task Num: | WBS 561581.02.08.07.15.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper summarizes the plans for the first Aeroelastic Prediction Workshop. The workshop is designed to assess the state of the art of computational methods for predicting unsteady flow fields and aeroelastic response. The goals are to provide an impartial forum to evaluate the effectiveness of existing computer codes and modeling techniques, and to identify computational and experimental areas needing additional research and development. Three subject configurations have been chosen from existing wind tunnel data sets where there is pertinent experimental data available for comparison. For each case chosen, the wind tunnel testing was conducted using forced oscillation of the model at specified frequencies |
| Meeting Information: | International Forum on Aeroelasticity and Structural Dynamics; June 26, 2011 - June 30, 2011; Paris; France |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | August 03, 2011 |
|
| NTRS Link | 20170001393 |
| Title: | Investigating the Transonic Flutter Boundary of the Benchmark Supercritical Wing |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170001393 |
| Author: | Heeg, Jennifer and Chwalowski, Pawel |
| NASA Center: | Langley Research Center |
| Publication Date: | January 09, 2017 |
| Document ID: | 20170001393 |
| Report/Patent Number: | NF1676L-26201 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper builds on the computational aeroelastic results published previously and generated in support of the second Aeroelastic Prediction Workshop for the NASA Benchmark Supercritical Wing configuration. The computational results are obtained using FUN3D, an unstructured grid Reynolds-Averaged Navier-Stokes solver developed at the NASA Langley Research Center. The analysis results focus on understanding the dip in the transonic flutter boundary at a single Mach number (0.74), exploring an angle of attack range of ��1 to 8 and dynamic pressures from wind off to beyond flutter onset. The rigid analysis results are examined for insights into the behavior of the aeroelastic system. Both static and dynamic aeroelastic simulation results are also examined. |
| Meeting Information: | AIAA SciTech Forum; January 09, 2017 - January 13, 2017; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | February 09, 2017 |
|
| NTRS Link | 20170000734 |
| Title: | Numerical Investigations of the Benchmark Supercritical Wing in Transonic Flow |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170000734 |
| Author: | Chwalowski, Pawel and Heeg, Jennifer and Biedron, Robert T. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 09, 2017 |
| Document ID: | 20170000734 |
| Report/Patent Number: | NF1676L-24500 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper builds on the computational aeroelastic results published previously and generated in support of the second Aeroelastic Prediction Workshop for the NASA Benchmark Supercritical Wing (BSCW) configuration. The computational results are obtained using FUN3D, an unstructured grid Reynolds-Averaged Navier-Stokes solver developed at the NASA Langley Research Center. The analysis results show the effects of the temporal and spatial resolution, the coupling scheme between the flow and the structural solvers, and the initial excitation conditions on the numerical flutter onset. Depending on the free stream condition and the angle of attack, the above parameters do affect the flutter onset. Two conditions are analyzed: Mach 0.74 with angle of attack 0 and Mach 0.85 with angle of attack 5. The results are presented in the form of the damping values computed from the wing pitch angle response as a function of the dynamic pressure or in the form of dynamic pressure as a function of the Mach number. |
| Meeting Information: | AIAA SciTech 2017; January 09, 2017 - January 17, 2017; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | January 25, 2017 |
|
| NTRS Link | 20170000312 |
| Title: | An Immersed Boundary Method for Solving the Compressible Navier-Stokes Equations with Fluid Structure Interaction |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170000312 |
| Author: | Brehm, Christoph and Barad, Michael F. and Kiris, Cetin C. |
| NASA Center: | Ames Research Center |
| Publication Date: | June 12, 2016 |
| Document ID: | 20170000312 |
| Report/Patent Number: | ARC-E-DAA-TN32637 |
| Contract/Grant/Task Num: | NNX15AW29G |
| Document Type: | Conference Paper |
| Abstract: | An immersed boundary method for the compressible Navier-Stokes equation and the additional infrastructure that is needed to solve moving boundary problems and fully coupled fluid-structure interaction is described. All the methods described in this paper were implemented in NASA's LAVA solver framework. The underlying immersed boundary method is based on the locally stabilized immersed boundary method that was previously introduced by the authors. In the present paper this method is extended to account for all aspects that are involved for fluid structure interaction simulations, such as fast geometry queries and stencil computations, the treatment of freshly cleared cells, and the coupling of the computational fluid dynamics solver with a linear structural finite element method. The current approach is validated for moving boundary problems with prescribed body motion and fully coupled fluid structure interaction problems in 2D and 3D. As part of the validation procedure, results from the second AIAA aeroelastic prediction workshop are also presented. The current paper is regarded as a proof of concept study, while more advanced methods for fluid structure interaction are currently being investigated, such as geometric and material nonlinearities, and advanced coupling approaches. |
| Meeting Information: | AIAA AVIATION 2016; June 13, 2016 - June 17, 2016; Washington, DC; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | January 11, 2017 |
|
| NTRS Link | 20130013394 |
| Title: | Experimental Data from the Benchmark SuperCritical Wing Wind Tunnel Test on an Oscillating Turntable |
| NTRS Full-Text: | http://hdl.handle.net/2060/20130013394 |
| Author: | Heeg, Jennifer and Piatak, David J. |
| NASA Center: | Langley Research Center |
| Publication Date: | April 08, 2013 |
| Document ID: | 20130013394 |
| Report/Patent Number: | AIAA Paper 2013-1802, NF1676L-15289 |
| Contract/Grant/Task Num: | WBS 136905.02.04.04.16.05 |
| Document Type: | Conference Paper |
| Abstract: | The Benchmark SuperCritical Wing (BSCW) wind tunnel model served as a semi-blind testcase for the 2012 AIAA Aeroelastic Prediction Workshop (AePW). The BSCW was chosen as a testcase due to its geometric simplicity and flow physics complexity. The data sets examined include unforced system information and forced pitching oscillations. The aerodynamic challenges presented by this AePW testcase include a strong shock that was observed to be unsteady for even the unforced system cases, shock-induced separation and trailing edge separation. The current paper quantifies these characteristics at the AePW test condition and at a suggested benchmarking test condition. General characteristics of the model's behavior are examined for the entire available data set. |
| Meeting Information: | 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference; April 08, 2013 - April 11, 2013; Boston, MA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | May 10, 2013 |
|
| NTRS Link | 20190027400 |
| Title: | An Evaluation and Recommendations for Further CFD Research Based on the NASA Common Research Model (CRM) Analysis from the AIAA Drag Prediction Workshop (DPW) Series |
| NTRS Full-Text: | http://hdl.handle.net/2060/20190027400 |
| Author: | Tinoco, Edward N. |
| NASA Center: | Langley Research Center |
| Publication Date: | June 01, 2019 |
| Document ID: | 20190027400 |
| Report/Patent Number: | CR-2019-220284, NF1676L-28402 |
| Contract/Grant/Task Num: | NNL09AA00A; 109492.02.07.01.01 |
| Document Type: | Contractor Report (CR) |
| Abstract: | The six Drag Prediction Workshops (DPW) have drawn a total of 125 participants submitting 225 data entries. Over half of these occurred in the last three workshops dealing with the NASA Common Research Model (CRM). Participants have ranged from North America, Europe, Asia, and South America, representing Government, Industry, Academia, and Commercial/Vendors. The DPW Series has generated a tremendous amount of CFD data, freely available to the public domain. A continuous improvement of the results as measured by: the reduction of the spread of drag predictions for the specified “nominal” cruise point, accuracy of drag increment, and the angle-of-attack sweep behavior, has been noted. Although it has been difficult separating out the parts and pieces that contribute to errors in CFD drag predictions, part of the improvements over the years can be attributed to grid resolution. The scatter in predicted drag in the continuum has been reduced dramatically from plus or minus 50 counts in DPW-I to around plus or minus 5 counts for DPW-V and - VI. During the six workshops, the grid size has grown dramatically. The average size of the medium wing-body meshes in DPW-I through DPW-IV have been 3.2, 5.4, 7.8 and 10.9 million, respectively. This represents a growth rate of approximately 17 percent per year during the eight years between DPW-I and DPW-IV. For DPW-VI, this number has grown from 25 to 50 million points for the various families of grids available. The finest level grids have increased steadily, from just over 3 million grid points in DPW-I to 225 million for the WBNP (Wing-Body-Nacelle-Pylon) in DPW-VI. While progress has been made, persistent problems with grid generation and separated flow prediction continue. The experiences and recommendations presented here are consistent with those espoused in the “CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences,” NASA/CR-2014-218178. |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Public use permitted |
| Date Acquired: | July 18, 2019 |
|
| NTRS Link | 20180007513 |
| Title: | Sensitivity Analysis for Multidisciplinary Systems (SAMS) |
| NTRS Full-Text: | http://hdl.handle.net/2060/20180007513 |
| Author: | Biedron, Robert T. and Jacobson, Kevin E. and Jones, William T. and Massey, Steven J. and Nielsen, Eric J. and Kleb, William L. and Zhang, Xinyu |
| NASA Center: | Langley Research Center |
| Publication Date: | September 01, 2018 |
| Document ID: | 20180007513 |
| Report/Patent Number: | NASA/TM-2018-220089, L-20932, NF1676L-30301 |
| Contract/Grant/Task Num: | NNX15AU22A; WBS 031102.02.07.05.93O4.17 |
| Document Type: | Technical Report |
| Abstract: | This report describes the research conducted under an interagency collaboration agreement between the Aerospace Systems Directorate of the Air Force Research Laboratory (AFRL/RQ) and the Computational AeroSciences Branch of NASA Langley (NASA LaRC). Both organizations have a long-term goal of developing a modular computational system for coupling fluids and structures to enable both analysis and optimization of aerospace vehicles. Ultimately, the system should support multiple solvers within the fluid and structure domains to allow the best combination for the task at hand, as well as to allow for institutional preferences of specific software components. Towards this goal, the current research was focused on enhancing the existing modal aeroelastic analysis in the NASA FUN3D (Fully-UNstructured three-dimensional CFD (Computational Fluid Dynamics) code) software (Biedron et al. 2018), as well as developing new aeroelastic analysis and optimization capabilities based on a non-linear finite-element method. The methods and enhancements described in this document pertain to FUN3D Version 13.4. |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Public use permitted |
| Date Acquired: | November 13, 2018 |
|
| NTRS Link | 20190027213 |
| Title: | Update on the Development of a Flutter Analysis Capability for Unconventional Aircraft Concepts Using HCDstruct |
| NTRS Full-Text: | http://hdl.handle.net/2060/20190027213 |
| Author: | Quinlan, Jesse R. and Gern, Frank H. |
| NASA Center: | Langley Research Center |
| Publication Date: | June 25, 2018 |
| Document ID: | 20190027213 |
| Report/Patent Number: | NF1676L-28621 |
| Contract/Grant/Task Num: | 081876.02.07.30.01 |
| Document Type: | Conference Paper |
| Abstract: | Following years of development, the Higher-fidelity Conceptual Design and structural optimization (HCDstruct) tool is being extended to support dynamic aeroservoelastic analysis and structural optimization for advanced aircraft concepts. These required enhancements include: the development of an aerodynamic matching routine for correcting Nastran’s doublet-lattice method aerodynamics; the implementation of control surface structural models; and the implementation of support for Nastran’s flutter solution sequence (SOL 145). This paper presents an update on the implementation of generalized control surface structural models and support for Nastran SOL 145. |
| Meeting Information: | 2018 AIAA Aviation Forum; Atlanta, GA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright; Work of the U.S. Government - Public use permitted |
| Date Acquired: | July 12, 2019 |
|
| NTRS Link | 20180006304 |
| Title: | CFD Model Of The Transonic Dynamics Tunnel With Applications |
| NTRS Full-Text: | http://hdl.handle.net/2060/20180006304 |
| Author: | Chwalowski, Pawel and Silva, Walter A. and Wieseman, Carol D. and Heeg, Jennifer |
| NASA Center: | Langley Research Center |
| Publication Date: | April 16, 2018 |
| Document ID: | 20180006304 |
| Report/Patent Number: | NF1676L-26585 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents the Computational Fluid Dynamics (CFD) model of the flow in the NASA Langley Research Center Transonic Dynamics Tunnel (TDT) with some recent applications. The TDT is a continuous-flow, closed circuit, slotted-test-section wind tunnel with a 16- by 16-foot test section with cropped corners. The tunnel was originally built as the 19-ft Pressure Tunnel in 1938, but it was converted to the current transonic tunnel in the 1950s, with capabilities to use either air or heavy gas at pressures from atmosphere down to near vacuum. In this study, experimental data acquired in the empty tunnel using R-134a as the test medium was used to calibrate the computational data. Experimental data from a recent TDT test of a full-span fighter configuration in air was then selected for comparison with the numerical data. During this test, the configuration experienced a flutter event in the transonic flow regime. Numerically, the flutter event is simulated both inside the CFD model of the TDT and in a classical free-air model. The preliminary results show that the wind-tunnel walls do not affect flutter prediction. |
| Meeting Information: | NATO AVT-284 Research Workshop; April 16, 2018 - April 18, 2018; Torino; Italy |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright; Work of the U.S. Government - Public use permitted |
| Date Acquired: | October 19, 2018 |
|
| NTRS Link | 20180006175 |
| Title: | High-Order Stabilized Finite Elements on Dynamic Meshes |
| NTRS Full-Text: | http://hdl.handle.net/2060/20180006175 |
| Author: | Anderson, W. Kyle and Newman, James C., III |
| NASA Center: | Langley Research Center |
| Publication Date: | January 08, 2018 |
| Document ID: | 20180006175 |
| Report/Patent Number: | NF1676L-27349 |
| Contract/Grant/Task Num: | WBS 109492.02.07.01.01 |
| Document Type: | Conference Paper |
| Abstract: | The development of dynamic mesh capability for turbulent flow simulations using the Streamlined Upwind Petrov-Galerkin (SUPG) discretization is described. The current work extends previous research to include high-order spatial accuracy, including the satisfaction of the discrete geometric conservation law (GCL) on curved elements. Two closely-related schemes are described and the ability of these schemes to satisfy the GCL, while also maintaining temporal accuracy and conservation is assessed. Studies indicate that although one scheme discretizes the time derivative in conservative form, both schemes exhibit temporal conservation errors that decrease according to the expected design order of accuracy. The source of the temporal conservation errors is examined, and it is demonstrated that many finite-volume and finite-element schemes can also be expected to have difficulty strictly satisfying conservation in time. The effects on conservation are examined and, while present in the simulations, are seen to be negligible for the problems considered. |
| Meeting Information: | AIAA SciTech; January 08, 2018 - January 12, 2018; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Public use permitted |
| Date Acquired: | October 16, 2018 |
|
| NTRS Link | 20180006182 |
| Title: | Summary of the 1st AIAA Geometry and Mesh Generation Workshop (GMGW-1) and Future Plans |
| NTRS Full-Text: | http://hdl.handle.net/2060/20180006182 |
| Author: | Chawner, John R. and Michal, Todd and Slotnick, Jeffrey P. and Rumsey, Christopher L. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 08, 2018 |
| Document ID: | 20180006182 |
| Report/Patent Number: | NF1676L-27367 |
| Contract/Grant/Task Num: | WBS 109492.02.07.01.01 |
| Document Type: | Conference Paper |
| Abstract: | The 1st AIAA Geometry and Mesh Generation Workshop (GMGW-1) was held in conjunction with the AIAA Aviation Forum and Exposition 2017 and in collaboration with the 3rd AIAA Computational Fluid Dynamics (CFD) High Lift Prediction Workshop (HiLiftPW-3). As the first AIAA workshop on these topics, GMGW-1's broad objectives were to assess the current state-of-the art in geometry preprocessing and mesh generation technology as well as software as applied to aircraft and spacecraft systems. The workshop was intended to identify and develop understanding of areas of needed improvement in terms of performance, accuracy, and applicability. It was also to provide a foundation for documenting best practices for geometry preprocessing and mesh generation. The genesis of GMGW-1 is found in the indictments levied against geometry preprocessing and mesh generation - not undeservedly - by the NASA CFD Vision 2030 Study. In order to create a reference against which future progress in geometry preprocessing and mesh generation can be measured, the organizers of GMGW-1, with the assistance of the organizers of HiLiftPW- 3, focused GMGW-1 on generation of meshes of the NASA High Lift Common Research Model (HL-CRM). Some of the generated meshes were provided for use by the participants in HiLiftPW-3. All meshes and the processes by which they were generated were analyzed by GMGW-1 as a first assessment of state of the art practices. The results of GMGW-1 added quantitative detail to known problem areas including geometry modeling, data interoperability, and amount of human intervention. They do provide a clear path toward a vision of geometry preprocessing and mesh generation in the year 2030. The next milepost along this path will be a second workshop. |
| Meeting Information: | AIAA SciTech; January 08, 2018 - January 12, 2018; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Public use permitted |
| Date Acquired: | October 16, 2018 |
|
| NTRS Link | 20180003377 |
| Title: | Navier-Stokes Equations Based Aeroelasticity of Supersonic Transport Including Short Period Oscillations |
| NTRS Full-Text: | http://hdl.handle.net/2060/20180003377 |
| Author: | Guruswamy, Guru |
| NASA Center: | Ames Research Center |
| Publication Date: | January 01, 2018 |
| Document ID: | 20180003377 |
| Report/Patent Number: | ARC-E-DAA-TN52950 |
| Document Type: | Preprint |
| Abstract: | There is renewed interest in developing new supersonic transports after the discontinuation of the Concorde supersonic jet, which was mostly limited for flights over trans-oceanic routes due to the severe noise of the sonic boom. In order to avoid the sonic boom, more slender configurations, such as the Low Boom Flight Demonstrator (LBFD) configuration, are being considered. The aeroelastic characteristics of these new supersonic transports can significantly differ from conventional aircraft. Both rigid and flexible body modes can play a significant role in aeroelastic stability. For unconventional configurations, such as aircraft with forward swept wings, the short period oscillation (SPO) has been found to significantly impact the aeroelastic response. SPO can occur due to unanticipated events such as gusts, abrupt maneuvering, etc. During the design of the Concorde, the effects of SPO was considered in detail, though its impact is not publically disclosed. Assuring stability of supersonic aircraft, particularly during descent from the supersonic Mach regime to the transonic regime, is critical. An aircraft can deviate from its normal descent trajectory due to coupling between flows and body motions. The effect of SPO needs to be considered in aeroelastic responses. Preliminary studies using quasi-steady aerodynamics show that the presence of SPO can lead to unstable response. The well-established Reynolds Averaged Navier-Stokes (RANS) equations, which are computationally feasible with current supercomputers, have been in use for aeroelastic computations for the last three decades. Recently, such efforts have begun to include trajectory motions; for instance, the effect of phugoid motion on stability is studied in Ref. 9 using the RANS equations. In this paper, the effect of SPO on aeroelastic responses of a typical supersonic transport is studied. |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright; Work of the U.S. Government - Public use permitted |
| Date Acquired: | August 08, 2018 |
|
| NTRS Link | 20190000713 |
| Title: | Grid Convergence for Three Dimensional Benchmark Turbulent Flows |
| NTRS Full-Text: | http://hdl.handle.net/2060/20190000713 |
| Author: | Diskin, Boris and Anderson, William K. and Pandya, Mohagna J. and Rumsey, Christopher L. and Thomas, James L. and Liu, Yi and Nishikawa, Hiroaki |
| NASA Center: | Langley Research Center |
| Publication Date: | December 27, 2017 |
| Document ID: | 20190000713 |
| Report/Patent Number: | NF1676L-27447 |
| Contract/Grant/Task Num: | WBS 109492.02.07.01.01 |
| Document Type: | Conference Paper |
| Abstract: | Grid convergence studies are performed to establish reference solutions for benchmark three dimensional turbulent flows in support of the ongoing turbulence model verification and validation e ort at the Turbulence Modeling Resource website curated by NASA. The bench- mark cases are a subsonic flow around a hemisphere cylinder and a transonic flow around the ONERA M6 wing with a sharp trailing edge. The study applies widely-used computational fluid dynamics codes developed and supported at the NASA Langley Research Center: FUN3D, USM3D, and CFL3D. Reference steady-state solutions are computed for the Reynolds-Averaged Navier-Stokes equations with the Spalart-Allmaras turbulence model on families of consistently-refined grids composed of different types of cells. Coarse-to- ne and code-to-code solution variation is described in detail. |
| Meeting Information: | AIAA SciTech 2018; January 08, 2018 - January 12, 2018; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Public use permitted |
| Date Acquired: | February 19, 2019 |
|
| NTRS Link | 20170009016 |
| Title: | Future of NASA's Aerosciences Capability |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170009016 |
| Author: | Schuster, David M. and D'Agostino, Mark G. |
| NASA Center: | Marshall Space Flight Center |
| Publication Date: | August 21, 2017 |
| Document ID: | 20170009016 |
| Report/Patent Number: | M17-6221 |
| Document Type: | Oral/Visual Presentation |
| Abstract: | No abstract available |
| Meeting Information: | Thermal & Fluids Analysis Workshop 2017 (TFAW); August 21, 2017 - August 25, 2017; Huntsville, AL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright; Work of the U.S. Government - Public use permitted |
| Date Acquired: | September 28, 2017 |
|
| NTRS Link | 20170011532 |
| Title: | CFD Vision 2030 and its Implementation |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170011532 |
| Author: | Rogers, Michael M. and Malik, Mujeeb R. |
| NASA Center: | Ames Research Center; Langley Research Center |
| Publication Date: | June 07, 2017 |
| Document ID: | 20170011532 |
| Report/Patent Number: | ARC-E-DAA-TN43439 |
| Document Type: | Oral/Visual Presentation |
| Abstract: | No abstract available |
| Meeting Information: | American Institute of Aeronautics and Astronautics (AIAA) Aviation 2017; June 05, 2017 - June 09, 2017; Denver, CO; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright; Work of the U.S. Government - Public use permitted |
| Date Acquired: | December 08, 2017 |
|
| NTRS Link | 20170001232 |
| Title: | Aeroelastic Uncertainty Quantification Studies Using the S4T Wind Tunnel Model |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170001232 |
| Author: | Nikbay, Melike and Heeg, Jennifer |
| NASA Center: | Langley Research Center |
| Publication Date: | January 09, 2017 |
| Document ID: | 20170001232 |
| Report/Patent Number: | NF1676L-24684 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper originates from the joint efforts of an aeroelastic study team in the Applied Vehicle Technology Panel from NATO Science and Technology Organization, with the Task Group number AVT-191, titled "Application of Sensitivity Analysis and Uncertainty Quantification to Military Vehicle Design." We present aeroelastic uncertainty quantification studies using the SemiSpan Supersonic Transport wind tunnel model at the NASA Langley Research Center. The aeroelastic study team decided treat both structural and aerodynamic input parameters as uncertain and represent them as samples drawn from statistical distributions, propagating them through aeroelastic analysis frameworks. Uncertainty quantification processes require many function evaluations to asses the impact of variations in numerous parameters on the vehicle characteristics, rapidly increasing the computational time requirement relative to that required to assess a system deterministically. The increased computational time is particularly prohibitive if high-fidelity analyses are employed. As a remedy, the Istanbul Technical University team employed an Euler solver in an aeroelastic analysis framework, and implemented reduced order modeling with Polynomial Chaos Expansion and Proper Orthogonal Decomposition to perform the uncertainty propagation. The NASA team chose to reduce the prohibitive computational time by employing linear solution processes. The NASA team also focused on determining input sample distributions. |
| Meeting Information: | AIAA SciTech 2017; January 09, 2017 - January 13, 2017; Grapevine, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | February 06, 2017 |
|
| NTRS Link | 20170000727 |
| Title: | A Bibliography of Transonic Dynamics Tunnel (TDT) Publications |
| NTRS Full-Text: | http://hdl.handle.net/2060/20170000727 |
| Author: | Doggett, Robert V. |
| NASA Center: | Langley Research Center |
| Publication Date: | December 01, 2016 |
| Document ID: | 20170000727 |
| Report/Patent Number: | NASA/TM-2016-219355, L-20739, NF1676L-25167 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Technical Report |
| Abstract: | The Transonic Dynamics Tunnel (TDT) at the National Aeronautics and Space Administration's (NASA) Langley Research Center began research operations in early 1960. Since that time, over 600 tests have been conducted, primarily in the discipline of aeroelasticity. This paper presents a bibliography of the publications that contain data from these tests along with other reports that describe the facility, its capabilities, testing techniques, and associated research equipment. The bibliography is divided by subject matter into a number of categories. An index by author's last name is provided. |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | January 25, 2017 |
|
| NTRS Link | 20160007678 |
| Title: | Development of a Prototype Model-Form Uncertainty Knowledge Base |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160007678 |
| Author: | Green, Lawrence L. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 04, 2016 |
| Document ID: | 20160007678 |
| Report/Patent Number: | NF1676L-21551 |
| Contract/Grant/Task Num: | WBS 109492.02.07.01.11.03 |
| Document Type: | Conference Paper |
| Abstract: | Uncertainties are generally classified as either aleatory or epistemic. Aleatory uncertainties are those attributed to random variation, either naturally or through manufacturing processes. Epistemic uncertainties are generally attributed to a lack of knowledge. One type of epistemic uncertainty is called model-form uncertainty. The term model-form means that among the choices to be made during a design process within an analysis, there are different forms of the analysis process, which each give different results for the same configuration at the same flight conditions. Examples of model-form uncertainties include the grid density, grid type, and solver type used within a computational fluid dynamics code, or the choice of the number and type of model elements within a structures analysis. The objectives of this work are to identify and quantify a representative set of model-form uncertainties and to make this information available to designers through an interactive knowledge base (KB). The KB can then be used during probabilistic design sessions, so as to enable the possible reduction of uncertainties in the design process through resource investment. An extensive literature search has been conducted to identify and quantify typical model-form uncertainties present within aerospace design. An initial attempt has been made to assemble the results of this literature search into a searchable KB, usable in real time during probabilistic design sessions. A concept of operations and the basic structure of a model-form uncertainty KB are described. Key operations within the KB are illustrated. Current limitations in the KB, and possible workarounds are explained. |
| Meeting Information: | 2016 AIAA SciTech Conference; January 04, 2016 - January 08, 2016; San Diego, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | June 20, 2016 |
|
| NTRS Link | 20160007531 |
| Title: | Reference Solutions for Benchmark Turbulent Flows in Three Dimensions |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160007531 |
| Author: | Diskin, Boris and Thomas, James L. and Pandya, Mohagna J. and Rumsey, Christopher L. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 04, 2016 |
| Document ID: | 20160007531 |
| Report/Patent Number: | NF1676L-21502 |
| Contract/Grant/Task Num: | WBS 109492.02.07.01.02.01 |
| Document Type: | Conference Paper |
| Abstract: | A grid convergence study is performed to establish benchmark solutions for turbulent flows in three dimensions (3D) in support of turbulence-model verification campaign at the Turbulence Modeling Resource (TMR) website. The three benchmark cases are subsonic flows around a 3D bump and a hemisphere-cylinder configuration and a supersonic internal flow through a square duct. Reference solutions are computed for Reynolds Averaged Navier Stokes equations with the Spalart-Allmaras turbulence model using a linear eddy-viscosity model for the external flows and a nonlinear eddy-viscosity model based on a quadratic constitutive relation for the internal flow. The study involves three widely-used practical computational fluid dynamics codes developed and supported at NASA Langley Research Center: FUN3D, USM3D, and CFL3D. Reference steady-state solutions computed with these three codes on families of consistently refined grids are presented. Grid-to-grid and code-to-code variations are described in detail. |
| Meeting Information: | 2016 AIAA SciTech Conference; January 04, 2016 - January 08, 2016; San Diego, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | June 16, 2016 |
|
| NTRS Link | 20160007539 |
| Title: | Computational Analysis of the Transonic Dynamics Tunnel Using FUN3D |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160007539 |
| External Online Source: | http://dx.doi.org/10.2514/6.2016-1775 |
| Author: | Chwalowski, Pawel and Quon, Eliot and Brynildsen, Scott E. |
| NASA Center: | Langley Research Center |
| Publication Date: | January 04, 2016 |
| Document ID: | 20160007539 |
| Report/Patent Number: | NF1676L-21467 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | This paper presents results from an exploratory two-year effort of applying Computational Fluid Dynamics (CFD) to analyze the empty-tunnel flow in the NASA Langley Research Center Transonic Dynamics Tunnel (TDT). The TDT is a continuous-flow, closed circuit, 16- x 16-foot slotted-test-section wind tunnel, with capabilities to use air or heavy gas as a working fluid. In this study, experimental data acquired in the empty tunnel using the R-134a test medium was used to calibrate the computational data. The experimental calibration data includes wall pressures, boundary-layer profiles, and the tunnel centerline Mach number profiles. Subsonic and supersonic flow regimes were considered, focusing on Mach 0.5, 0.7 and Mach 1.1 in the TDT test section. This study discusses the computational domain, boundary conditions, and initial conditions selected and the resulting steady-state analyses using NASA's FUN3D CFD software. |
| Meeting Information: | AIAA Science and Technology Forum and Exposition; January 04, 2016 - January 08, 2016; San Diego, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | June 16, 2016 |
|
| NTRS Link | 20160005041 |
| Title: | Towards an Aero-Propulso-Servo-Elasticity Analysis of a Commercial Supersonic Transport |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160005041 |
| Author: | Connolly, Joseph W. and Kopasakis, George and Chwalowski, Pawel and Sanetrik, Mark D. and Carlson, Jan-Renee and Silva, Walt A. and McNamara, Jack |
| NASA Center: | Glenn Research Center; Langley Research Center |
| Publication Date: | January 04, 2016 |
| Document ID: | 20160005041 |
| Report/Patent Number: | GRC-E-DAA-TN28432 |
| Contract/Grant/Task Num: | WBS 110076.02.03.03.11 |
| Document Type: | Conference Paper |
| Abstract: | This paper covers the development of an aero-propulso-servo-elastic (APSE) model using computational fluid dynamics (CFD) and linear structural deformations. The APSE model provides the integration of the following two previously developed nonlinear dynamic simulations: a variable cycle turbofan engine and an elastic supersonic commercial transport vehicle. The primary focus of this study is to provide a means to include relevant dynamics of a turbomachinery propulsion system into the aeroelastic studies conducted during a vehicle design, which have historically neglected propulsion effects. A high fidelity CFD tool is used here for the integration platform. The elastic vehicle neglecting the propulsion system serves as a comparison of traditional approaches to the APSE results. An overview of the methodology is presented for integrating the propulsion system and elastic vehicle. Static aeroelastic analysis comparisons between the traditional and developed APSE models for a wing tip detection indicate that the propulsion system impact on the vehicle elastic response could increase the detection by approximately ten percent. |
| Meeting Information: | AIAA SciTech Forum 2016; January 04, 2016 - January 08, 2016; San Diego, CA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | April 18, 2016 |
|
| NTRS Link | 20160006014 |
| Title: | Ongoing Fixed Wing Research within the NASA Langley Aeroelasticity Branch |
| NTRS Full-Text: | http://hdl.handle.net/2060/20160006014 |
| Author: | Bartels, Robert and Chwalowski, Pawel and Funk, Christie and Heeg, Jennifer and Hur, Jiyoung and Sanetrik, Mark and Scott, Robert and Silva, Walter and Stanford, Bret and Wiseman, Carol |
| NASA Center: | Langley Research Center |
| Publication Date: | June 22, 2015 |
| Document ID: | 20160006014 |
| Report/Patent Number: | NF1676L-20156 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.08 |
| Document Type: | Conference Paper |
| Abstract: | The NASA Langley Aeroelasticity Branch is involved in a number of research programs related to fixed wing aeroelasticity and aeroservoelasticity. These ongoing efforts are summarized here, and include aeroelastic tailoring of subsonic transport wing structures, experimental and numerical assessment of truss-braced wing flutter and limit cycle oscillations, and numerical modeling of high speed civil transport configurations. Efforts devoted to verification, validation, and uncertainty quantification of aeroelastic physics in a workshop setting are also discussed. The feasibility of certain future civil transport configurations will depend on the ability to understand and control complex aeroelastic phenomena, a goal that the Aeroelasticity Branch is well-positioned to contribute through these programs. |
| Meeting Information: | AIAA Aviation 2015; June 22, 2015 - June 26, 2015; Dallas, TX; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | May 13, 2016 |
|
| NTRS Link | 20150005716 |
| Title: | Grid Convergence for Turbulent Flows(Invited) |
| NTRS Full-Text: | http://hdl.handle.net/2060/20150005716 |
| Author: | Diskin, Boris and Thomas, James L. and Rumsey, Christopher L. and Schwoppe, Axel |
| NASA Center: | Langley Research Center |
| Publication Date: | January 05, 2015 |
| Document ID: | 20150005716 |
| Report/Patent Number: | NF1676L-18876 |
| Contract/Grant/Task Num: | NNL09AA00A; WBS 794072.02.07.02.01 |
| Document Type: | Conference Paper |
| Abstract: | A detailed grid convergence study has been conducted to establish accurate reference solutions corresponding to the one-equation linear eddy-viscosity Spalart-Allmaras turbulence model for two dimensional turbulent flows around the NACA 0012 airfoil and a flat plate. The study involved three widely used codes, CFL3D (NASA), FUN3D (NASA), and TAU (DLR), and families of uniformly refined structured grids that differ in the grid density patterns. Solutions computed by different codes on different grid families appear to converge to the same continuous limit, but exhibit different convergence characteristics. The grid resolution in the vicinity of geometric singularities, such as a sharp trailing edge, is found to be the major factor affecting accuracy and convergence of discrete solutions, more prominent than differences in discretization schemes and/or grid elements. The results reported for these relatively simple turbulent flows demonstrate that CFL3D, FUN3D, and TAU solutions are very accurate on the finest grids used in the study, but even those grids are not sufficient to conclusively establish an asymptotic convergence order. |
| Meeting Information: | AIAA Science and Technology Forum and Exposition (AIAA SciTech 2015); January 05, 2015 - January 09, 2015; Kissimmee, FL; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | April 17, 2015 |
|
| NTRS Link | 20140017729 |
| Title: | High-Lift OVERFLOW Analysis of the DLR-F11 Wind Tunnel Model |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140017729 |
| Author: | Pulliam, Thomas H. and Sclafani, Anthony J. |
| NASA Center: | Ames Research Center |
| Publication Date: | June 20, 2014 |
| Document ID: | 20140017729 |
| Report/Patent Number: | ARC-E-DAA-TN15438 |
| Document Type: | Conference Paper |
| Abstract: | In response to the 2nd AIAA CFD High Lift Prediction Workshop, the DLR-F11 wind tunnel model is analyzed using the Reynolds-averaged Navier-Stokes flow solver OVERFLOW. A series of overset grids for a bracket-off landing configuration is constructed and analyzed as part of a general grid refinement study. This high Reynolds number (15.1 million) analysis is done at multiple angles-of-attack to evaluate grid resolution effects at operational lift levels as well as near stall. A quadratic constitutive relation recently added to OVERFLOW for improved solution accuracy is utilized for side-of-body separation issues at low angles-of-attack and outboard wing separation at stall angles. The outboard wing separation occurs when the slat brackets are added to the landing configuration and is a source of discrepancy between the predictions and experimental data. A detailed flow field analysis is performed at low Reynolds number (1.35 million) after pressure tube bundles are added to the bracket-on medium grid system with the intent of better understanding bracket/bundle wake interaction with the wing's boundary layer. Localized grid refinement behind each slat bracket and pressure tube bundle coupled with a time accurate analysis are exercised in an attempt to improve stall prediction capability. The results are inconclusive and suggest the simulation is missing a key element such as boundary layer transition. The computed lift curve is under-predicted through the linear range and over-predicted near stall, and the solution from the most complete configuration analyzed shows outboard wing separation occurring behind slat bracket 6 where the experiment shows it behind bracket 5. These results are consistent with most other participants of this workshop. |
| Meeting Information: | Aviation 2014; June 16, 2014 - June 20, 2014; Atlanta, GA; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | January 08, 2015 |
|
| NTRS Link | 20140003093 |
| Title: | CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140003093 |
| Author: | Slotnick, Jeffrey and Khodadoust, Abdollah and Alonso, Juan and Darmofal, David and Gropp, William and Lurie, Elizabeth and Mavriplis, Dimitri |
| NASA Center: | Langley Research Center |
| Publication Date: | March 01, 2014 |
| Document ID: | 20140003093 |
| Report/Patent Number: | NASA/CR-2014-218178, NF1676L-18332 |
| Contract/Grant/Task Num: | NNL08AA16B; NNL12AD05T; WBS 794072.02.07.02.03 |
| Document Type: | Technical Report |
| Abstract: | This report documents the results of a study to address the long range, strategic planning required by NASA's Revolutionary Computational Aerosciences (RCA) program in the area of computational fluid dynamics (CFD), including future software and hardware requirements for High Performance Computing (HPC). Specifically, the "Vision 2030" CFD study is to provide a knowledge-based forecast of the future computational capabilities required for turbulent, transitional, and reacting flow simulations across a broad Mach number regime, and to lay the foundation for the development of a future framework and/or environment where physics-based, accurate predictions of complex turbulent flows, including flow separation, can be accomplished routinely and efficiently in cooperation with other physics-based simulations to enable multi-physics analysis and design. Specific technical requirements from the aerospace industrial and scientific communities were obtained to determine critical capability gaps, anticipated technical challenges, and impediments to achieving the target CFD capability in 2030. A preliminary development plan and roadmap were created to help focus investments in technology development to help achieve the CFD vision in 2030. |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution under U.S. Government purpose rights; under NASA contract NNL08AA16B |
| Date Acquired: | April 16, 2014 |
|
| NTRS Link | 20140011551 |
| Title: | Static Aeroelastic Analysis with an Inviscid Cartesian Method |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140011551 |
| Author: | Rodriguez, David L. and Aftosmis, Michael J. and Nemec, Marian and Smith, Stephen C. |
| NASA Center: | Ames Research Center |
| Publication Date: | January 13, 2014 |
| Document ID: | 20140011551 |
| Report/Patent Number: | ARC-E-DAA-TN12599 |
| Contract/Grant/Task Num: | NNA10DF26C |
| Document Type: | Conference Paper |
| Abstract: | An embedded-boundary, Cartesian-mesh flow solver is coupled with a three degree-of-freedom structural model to perform static, aeroelastic analysis of complex aircraft geometries. The approach solves a nonlinear, aerostructural system of equations using a loosely-coupled strategy. An open-source, 3-D discrete-geometry engine is utilized to deform a triangulated surface geometry according to the shape predicted by the structural model under the computed aerodynamic loads. The deformation scheme is capable of modeling large deflections and is applicable to the design of modern, very-flexible transport wings. The coupling interface is modular so that aerodynamic or structural analysis methods can be easily swapped or enhanced. After verifying the structural model with comparisons to Euler beam theory, two applications of the analysis method are presented as validation. The first is a relatively stiff, transport wing model which was a subject of a recent workshop on aeroelasticity. The second is a very flexible model recently tested in a low speed wind tunnel. Both cases show that the aeroelastic analysis method produces results in excellent agreement with experimental data. |
| Meeting Information: | Science and Technology Forum and Exposition (SciTech2014); January 13, 2014 - January 17, 2014; National Harbor Maryland; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | December 01, 2014 |
|
| NTRS Link | 20140007356 |
| Title: | Toward Improved CFD Predictions of Slender Airframe Aerodynamics Using the F-16XL Aircraft (CAWAPI-2) |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140007356 |
| Author: | Luckring, James M. and Rizzi, Arthur and Davis, M. Bruce |
| NASA Center: | Langley Research Center |
| Publication Date: | January 13, 2014 |
| Document ID: | 20140007356 |
| Report/Patent Number: | AIAA Paper-2014-0419, NF1676L-16698 |
| Contract/Grant/Task Num: | WBS 432938.11.01.07.43.40.01 |
| Document Type: | Conference Paper |
| Abstract: | A coordinated project has been underway to improve CFD predictions of slender airframe aerodynamics. The work is focused on two flow conditions and leverages a unique flight data set obtained with an F-16XL aircraft. These conditions, a low-speed high angleof- attack case and a transonic low angle-of-attack case, were selected from a prior prediction campaign wherein the CFD failed to provide acceptable results. In this paper the background, objectives and approach to the current project are presented. The work embodies predictions from multiple numerical formulations that are contributed from multiple organizations, and the context of this campaign to other multi-code, multiorganizational efforts is included. The relevance of this body of work toward future supersonic commercial transport concepts is also briefly addressed. |
| Meeting Information: | 52nd AIAA Aerospace Sciences Meeting; January 13, 2014 - January 17, 2014; National Harbor, MD; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | Copyright; Distribution as joint owner in the copyright |
| Date Acquired: | July 07, 2014 |
|
| NTRS Link | 20140007309 |
| Title: | Evaluation of Linear, Inviscid, Viscous, and Reduced-Order Modeling Aeroelastic Solutions of the AGARD 445.6 Wing Using Root Locus Analysis |
| NTRS Full-Text: | http://hdl.handle.net/2060/20140007309 |
| Author: | Silva, Walter A. and Perry, Boyd III and Chwalowski, Pawel |
| NASA Center: | Langley Research Center |
| Publication Date: | January 13, 2014 |
| Document ID: | 20140007309 |
| Report/Patent Number: | AIAA Paper 2014-0496, NF1676-16636 |
| Contract/Grant/Task Num: | WBS 475122.02.07.07.02 |
| Document Type: | Conference Paper |
| Abstract: | Reduced-order modeling (ROM) methods are applied to the CFD-based aeroelastic analysis of the AGARD 445.6 wing in order to gain insight regarding well-known discrepancies between the aeroelastic analyses and the experimental results. The results presented include aeroelastic solutions using the inviscid CAP-TSD code and the FUN3D code (Euler and Navier-Stokes). Full CFD aeroelastic solutions and ROM aeroelastic solutions, computed at several Mach numbers, are presented in the form of root locus plots in order to better reveal the aeroelastic root migrations with increasing dynamic pressure. Important conclusions are drawn from these results including the ability of the linear CAP-TSD code to accurately predict the entire experimental flutter boundary (repeat of analyses performed in the 1980's), that the Euler solutions at supersonic conditions indicate that the third mode is always unstable, and that the FUN3D Navier-Stokes solutions stabilize the unstable third mode seen in the Euler solutions. |
| Meeting Information: | 55th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference; January 13, 2014 - January 17, 2014; National Harbor, MD; United States |
| Distribution Limits: | Unclassified; Publicly available; Unlimited |
| Rights: | No Copyright |
| Date Acquired: | July 03, 2014 |
|