Aeroelastic Prediction Validation Technical Working Group Telecon Slides

Aeroelastic Prediction & Validation Technical Working Group Telecon Slides Oct 6, 2016 Aeroelastic Prediction & Validation Technical Working Group

Action items • Send out information regarding IFASD 2017 • Como, Italy • Abstract deadline: November 14, 2016 • Abstract: Less than 4 pages total. A minimum of 500 and a maximum of 1500 words • http: //congressi. fondazionealessandrovolta. it/ifasd 2017/abstract-submission/ • Marcello Righi and Cetin Kiris to correspond regarding papers and/or abstracts from the 2 meetings that Marcello attended • Send BSCW OTT experimental data summary to Marcello Righi (Jen Heeg) Aeroelastic Prediction & Validation Technical Working Group

Telecon agenda, Oct 6, 2016 • Review of last telecon • Administrivia • Progress towards Sci. Tech 2017 • Presentation at HRML 6 Meeting by Marcello Righi • Quick review of experimental data points • Ae. PW-2 Case # 3 results progress. • Technion results update: Daniella Raveh • NASA results update: Pawel Chwalowski • Validation testing • Your issue that you want to discuss goes here • Next telecon Nov 3, 2016, 11 a. m. • Telecon notices will only be sent if the time or date moves. Otherwise, please plan to the first Thursday of the month at 11 a. m. U. S. east coast time. Aeroelastic Prediction & Validation Technical Working Group 3

Summary of Sept telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon held Sept 1, 2016 • Next telecon Nov 3, 11 a. m. East Coast time in U. S. • Carlos Breviglieri, Embraer, presented results from the DPW Case #5 Aeroelastic analyses from Embraer. (https: //aiaa-dpw. larc. nasa. gov/Workshop 6/presentations/1_13_DPW 6 -PRESENTATION-EMBRAER. pdf) • Pawel Chwalowski, NASA, presented pertinent summary points from DPW • Upcoming Sci. Tech conference discussed. Papers are interspersed in 4 sessions on Monday and Tuesday. • Presentation of Ae. PW to NASA Associate Administrator, Jaiwan Shin. It appears that there is a good deal of buy-in at the highest levels of NASA, regarding conducting these validation experiments. He was very interested to hear about partners in the collaborative effort. • Validation experiment discussion • Delayed discussion of Ae. PW-2 Case #3 results until October • Technion results update: Daniella Raveh • NASA results update: Pawel Chwalowski Aeroelastic Prediction & Validation Technical Working Group 4

2017 AIAA Sci. Tech Conference: Jan 9 -17, 2017, Grapevine Texas • Sessions have been set • Dec 6, 2016: Manuscript deadline • We had multiple papers cancelled at the last minute. For the Sci. Tech, if you know that you have to pull your paper, please let me know as soon as you know, so that the sessions can be reorganized or combined. Aeroelastic Prediction & Validation Technical Working Group

Presentations by Marcello Righi • ETMM 11 (ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements) in Palermo (Italy) • 6 th Symposium on Hybrid RANS-LES Methods in Strasbourg (France) HRLM 6 Meeting (https: //hrlm 6. sciencesconf. org/) focusing on hybrid RANSLES turbulence modelling. Sept 28, 2016 • Presented results from the Hybrid RANS-Les modeling of the BSCW • Hybrid RANS-LES modelling might be able to improve predictions - at a much higher computational cost of course - but additional experiments are necessary to: - quantify the improvement wrt URANS in terms of e. g. FRF, - identify the physical mechanisms responsible for the improvement (e. g. more accurate shock - BL interaction, better resolution of wake, better resolution of turbulent scale of motion, interaction between the latter and the forcing frequencies? . . . ) Aeroelastic Prediction & Validation Technical Working Group

Discussion on Oct Telecon re: Conferences that Marcello attended • There was surprise in the spread of flutter predictions at Mach 0. 85, 5 degs • There was a good deal of experimental work presented, including using PIV, from primarily European groups (e. g. , DLR, ONERA, also Calgary) • There were numerous sessions on RANS-LES methods. Cetin Kiris: 2 issues with the hybrid methods: 1) shielding function; 2) grey zone. Were these discussed? Marcello: Virtually all presentations included discussion of the grey zone. Cetin: What about Menter’s shielding function? Did he give specifics on that? Marcello: No, no details were given. Menter explained in broad terms. This shielding function is ANSYS proprietary, and would be too complex to explain in a conference presentation. Aeroelastic Prediction & Validation Technical Working Group

Available experimental flutter data sets for BSCW PAPA Mach Aeroelastic Prediction & Validation Technical Working Group 0. 435 0. 579 0. 689 0. 742 0. 797 0. 798 0. 799 0. 801 0. 803 0. 817 0. 823 0. 319 0. 326 0. 335 0. 503 0. 509 0. 513 0. 619 0. 679 0. 725 0. 738 0. 762 0. 766 0. 769 aoa (degs) -0. 3 -0. 2 -0. 1 0 5. 5 1. 3 5. 4 0 0 0 -0. 1 1 0 -0. 2 0 1 -0. 4 -0. 1 1. 2 -0. 1 1. 2 0 qbar gamma (psf) 157. 4 1. 138 162. 4 1. 136 169. 3 1. 135 168. 8 1. 136 172. 6 1. 134 93. 6 1. 135 166. 9 1. 134 105. 5 1. 135 124. 7 1. 135 170. 7 1. 134 178. 8 1. 134 177. 5 1. 134 140. 3 1. 401 145. 1 1. 401 155. 5 1. 402 160. 1 1. 401 152. 2 1. 401 156. 4 1. 401 168. 2 1. 401 171. 1 1. 4 170. 2 1. 4 172. 4 177. 6 1. 4 173. 8 1. 4 169. 3 1. 4 168. 9 1. 4

Ae. PW – 2 Case # 3 Progress Aeroelastic Prediction & Validation Technical Working Group

Discussion of Technion flutter analyses • Case 3: Mach 0. 85 5 degs case • Has same prediction as at Aviation, but higher confidence now. At Aviation was based on reduced order model. • 345 psf flutter onset (slowly decaying here) • File of results: ROM_flutter_M 085_Daniella. Raveh. pdf Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Discussion of Daniella’s analyses; Points that Daniella made • The analyses use heave and pitch responses to each mode being separately excited, i. e. , the modes are excited, one at a time and a separate simulation is performed for each modal excitation • The excitations that are used are filtered white noise modal displacement time histories. The filter is a low pass filter with cut-off frequency of 12. 5 Hz. • Output data: the FRFs are used to generate the GAFs • The aerodynamic ROM on slide 3 is for Ae. PW-2 Case #3 (Mach 0. 85, 5 degs) • The CFD results and ROM results were generated using URANS with a Menter SST turbulence model. • The process is to use a ROM that resembles a linear analysis framework, replacing the linear aerodynamic GAF’s with GAFs based on CFD. Aeroelastic Prediction & Validation Technical Working Group

Discussion of NASA Case 3 progress, Pawel Chwalowski • Case 3: Mach 0. 85 5 degs case • Fine grid results, with and without limiter • On fine grid, flutter onset prediction is between 375 and 425 psf • Preparing detailed results for Sci. Tech conference Aeroelastic Prediction & Validation Technical Working Group

Validation Testing • Proposed to and supported by NASA Aeronautics Research Mission Directorate, Transformative Tools and Technologies Project • Forming team that includes NASA participants from • • Aeroelasticity Group Instrumentation and Measurement Systems Group Multidisciplinary Optimization Group Possibly include? Computational Methods Group • Participation, interest from outside of NASA is encouraged • No framework formulated yet for outside-of-NASA partnering Aeroelastic Prediction & Validation Technical Working Group

Major milestone proposal submitted to NASA planning team See next slide for enlarged categories Aeroelastic Prediction & Validation Technical Working Group

RM =Rigid Model, AM = Aeroelastic Model Milestones & Decision Gates Evaluation of optical methods for testing in the Transonic Dynamics Tunnel, July 2017 Conceptual design completion, rigid model (OML design evaluation decision), August 2017 Comparison of rigid data: computational predictions and experiment, Jan 2019 Conceptual design completion, aeroelastic model, Feb 2019 Comparison of aeroelastic data: computational predictions and experiment, July 2020 Wind Tunnel Tests Optical methods evaluation test, March 2017 Rigid model test, August 2018 Aeroelastic test, Feb 2020 Aeroelastic Prediction & Validation Technical Working Group

General material and prior telecon summaries Aeroelastic Prediction & Validation Technical Working Group 23

Presentations of Ae. PW-2 material • Presentation to the NASA associate administrator for aeronautics (J. Heeg, August 25, 2016) • Presentation Aerospace Flutter and Dynamics Council meeting (Eric Blades, San Diego, Nov 5 -6, 2015) Lots of opinions regarding path forward • Presentation made of workshop summary to date at the Aerospace Flutter and Dynamics Council meeting (Washington D. C. , May 12 -13, 2016) Linear analysis seems to be good enough over most of the range of conditions. • Presentation made of workshop summary to date to Boeing Technical Center of Excellence (March 2016) • Presentations made of Aviation conference material to NASA (Hampton Virginia, USA, June 1, 2016) • FUN 3 D results, Pawel Chwalowski Grid convergence: Are solutions grid converged? Current thoughts are that for STEADY distributed parameters, a 2 D section analysis at ? Condition, requires 16 M grid points for spatial convergence ; Limiter vs No Limiter: As you go to finer grid resolution, the limiter vs no limiter differences should disappear; Structural damping effect: Since none of the workshop analyses contained non-zero structural damping, is this something that should still be examined? A lot of the results from the workshop are below the experimental prediction. How much influence does this have? Temporal convergence: Lots of interest in what we did. Discussion regarding evaluation of different conditions. • Overview, Jennifer Heeg • Are there other presentations of material that we can add to this list? It would like to document this if practical. Aeroelastic Prediction & Validation Technical Working Group

Summary of August telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon held Aug 4, 2016 • Next telecon Oct 6, 11 a. m. East Coast time in U. S. • Technion flutter results update • Validation experiment discussed • Action items for Sept 1 telecon: • DPW Case #5 Aeroelastic analyses from Embraer. Present results on Sept telecon • Summary of DPW as pertains to aeroelasticity (Pawel Chwalowski) • Ae. PW-2 Case # 3 results progress. • Technion results update: Daniella Raveh • NASA results update: Pawel Chwalowski • Touch base with Embraer POC regarding in-house planning (Cleber Spode? My notes didn’t say who was going to do this. ) Can they present a big picture overview for the Sept telecon? • Aviation conference debrief: Summarize discussion etc (all); Send to Jen (all); Compile for Sept telecon (Jen) • Validation experiment discussion: Summarize current telecon (Jen) • SDTC meeting summary and Sci. Tech status report of Ae. PW special sessions (Eric Blades) Aeroelastic Prediction & Validation Technical Working Group 25

Sci. Tech 2017 • Session #: SD-03 Session Title: Special Session: Aeroelastic Prediction I Session Time: January 9, 2017 from 9: 30 AM to 12: 30 PM, in Appaloosa 4 • Session #: SD-06 Session Title: Special Session: Aeroelastic Prediction II Session Time: January 9, 2017 from 2: 00 PM to 5: 00 PM, in Appaloosa 4 • Session #: SD-09 Session Title: Special session: Aeroelastic Prediction III Session Time: January 10, 2017 from 9: 30 AM to 12: 30 PM, in Appaloosa 4 • Session #: SD-12 Session Title: Special Session: Aeroelastic Prediction IV Session Time: January 10, 2017 from 2: 00 PM to 5: 00 PM, in Appaloosa 4 Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Aeroelastic Prediction & Validation Technical Working Group

Sci. Tech 2017 Special Session Abstracts Control ID Session Time Title 2550711 Jennifer Heeg, Pawel Chwalowski Linking the physics and the data: Considerations of the computational and experimental data from the Aeroelastic Prediction Workshops 2550438 Pawel Chwalowski, Jennifer Heeg, Bob Biedron Numerical Investigations of the Benchmark Supercritical Wing in Transonic Flow 2547890 Jan Navratil, Adam Jirasek, Mats Dalenbring Effect of angle of attack and gas properties on flutter boundary of Benchmark Super-Critical Wing 2551284 Krishna Zore, Bala Sasanapuri, Eric Bish Aeroelastic Simulations using ANSYS Multiphysics Software 2548900 Cleber Spode, Eduardo S. Molina, Roberto Gil Annes da Silva Plans and Suggestions for a Verification Case to the AIAA Aeroelastic Prediction Workshop 2551854 Authors Overset Grid Simulation for the Second AIAA Aeroelastic Prediction Workshop 2551338 Marcello Righi Analysis of Resolved Turbulent Scales of Motion in Aeroelastic Problems 2552540 Eric Blades, A. Cornish Aeroelastic Simulations for the Second Aeroelastic Prediction Workshop using Loci/CHEM 2552548 Amin Fedeirooni Development of an Enhanced Open. FOAM-based CFD Solver and its Application to Aeroelastic Problems Aeroelastic Prediction & Validation Technical Working Group

DPW 6 Notes and Conclusions: (Pawel Chwalowski interpretation) DPW 6: http: //aiaa-dpw. larc. nasa. gov/Workshop 6/ CRM has its own website: https: //commonresearchmodel. larc. nasa. gov DPW considered six grid resolutions in their analysis: tiny, coarse, medium, fine, xfine, and ultra fine. Two sets of grid were provided: Unstructured by NASA, and Overset by Boeing. • The grids size varied from 7. 4 M to 83 M nodes. • The CRM which was tested at JAXA and ONERA is not the same as tested in NTF and ETW. JAXA and ONERA built their own scaled version of the CRM. • Sting might have an effect on aerodynamic forces. CFD models did not include sting. • The predominant choice of the turbulence model at DPW was SA either QCR 200 (Quadratic Constitutive Relation) or RC (Rotation/Curvature Correction). • DPW asked for the mass flow rate through the nacelle, but nobody supplied the number. • Strong effects of the Venkatakrishnan limiter. Very nice presentation by JAXA. With limiter, shock moved farther aft on the wing. • CFD++ / DLR / Embraer were the only three teams which showed coupled static aeroelastic analysis. • Some teams needed to recreate the grid for rigid analysis in order to do static aeroelastic analysis. It is not clear why. • CFD++ examined in great detail normal and shear stresses. • Embraer used modal approach in static aeroelastic analysis with 10 modes only. • Grid adaptation results. Interesting, but not conclusive if the adaptation is needed. • Most codes have automated CL driver to obtain the desired CL value. • Static aeroelastic and rigid results showed, in general, shock location aft of the experimental data. • The computed static aeroelastic twist angle among three teams did not match, and it did not match perfectly the experimental data. • The statistics of the DPW results were shown as a Box/Violin plots. • No clear path forward. • The experimental data was not measured using unsteady pressure transducers. The bounds and shock motion is unknown. • Exa showed the animation of the moving shock. Clearly the term “steady” is not true. At Mach 0. 85 Ao. A = 4 deg the flow is very unsteady. The animation reminded me of our Ae. PW results. • The presentations are on the DPW website. Aeroelastic Prediction & Validation Technical Working Group • • •

Summary of June telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon held June 2, 2016 • Next telecon Aug 4, 11 a. m. East Coast time in U. S. • Aviation special sessions discussed • Sci. Tech Jan 2017 abstracts discussed. Individuals organizations are submitting individual abstracts rather than analysis teams combining to publish. • Final versions of database comparisons shown and last minute issues resolved. • Next steps in our validation quest discussed. Slides included in this slide set for continued discussion as time allows. Aeroelastic Prediction & Validation Technical Working Group 31

Summary of May telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon held May 5. • Next telecon June 2, 11 a. m. East Coast time in U. S. • Aviation special session abstracts shown; sessions as they existed on AIAA website shown. Dave Schuster and Daniella Ravey to co-chair each of the two sessions with Jen as co-chair. • Special session at Sci. Tech Jan 2017: abstracts due Monday June 6, 2016 • Database comparison files had been distributed to each analysis team, showing only their results vs. experimental data. (May 4, 2016). • Modified results for 4 teams were received and/or corrected. • Telecons held and email correspondences to correct data Aeroelastic Prediction & Validation Technical Working Group 32

The following 4 slides are from the May telecon Aeroelastic Prediction & Validation Technical Working Group

Next Steps? • Are you interested in working on cooperative papers for Sci. Tech? IFASD? • We did this for the 2013 IFASD. It was work, but the combined publications were much better than any of the individual analysis papers. • Statistical analysis of comparison results • Data reduction and comparison of integrated quantity frequency response functions • Going beyond Ae. PW-2 to learn more about: • Numerical damping effects (including temporal convergence requirement, influence of limiter) • Does coupling method matter? • Influence of separation? Do we have additional analyses, codes that can be applied to the Mach 0. 85 5 deg case? • Analysis across the Mach-alpha envelope • Separate the effects of shock strength, shock location, lower surface aft loading • Turbulence Models: Can we follow some of the logic and wisdom that Yuval offered? • Higher fidelity analysis tools Aeroelastic Prediction & Validation Technical Working Group 34

NASA Management Highlight • Computational predictions of flutter onset showed good agreement with experimental data for the designated benchmarking test case (low transonic Mach number, 0°angle of attack (pink line in figure). Weak shocks and small separated flow regions were predicted at this condition. • Linear predictions produced comparable results at this condition (blue line in figure). • At the more aggressive optional analysis condition, where no experimental flutter onset data is available and the predicted flow conditions include strong shocks with dominant separated flow regions, the predictions varied widely (orange line in figure). Aeroelastic Prediction & Validation Technical Working Group Ranges of High-Fidelity Computational Results Mach 0. 74 Mach 0. 85 Linear Analysis Results Experiment TDT operating envelope

Big Questions Remain • Why do our flutter predictions for Case 3 vary so widely? • What can we do to understand the underlying causes? • What can we do to improve the predictions? • Does the coupling methodology matter? (loose vs strong, using Ae. PW-2 language) • What are the critical features that induce flutter? Do these critical features vary by flow condition? (e. g. Shock formation, separated flow onset, separation-reattachment cycles and phasing, modal interactions) • Process: • How should we approach flutter solutions using current CFD methodologies? • How should we recommend modification of CFD methodologies to better suit flutter prediction? Aeroelastic Prediction & Validation Technical Working Group 36

Some big picture comments & questions: Computational • The process that we used to obtain flutter predictions from FUN 3 D was improvisational. We need something better. • Process used required intensive matrix to differentiate Numerical vs Physical damping • Desired: • Integrated assessment of physical damping prediction • Integrated process to drive system to a physical prediction of damping (rather than the primary result that we seemed to achieve which is a study of numerical damping) • What is the “right way” to do temporal convergence? If I had it to do all over again, would I, could I: • Perform Time-accurate analysis of the uncoupled flow field. Drive it until the answers (what parameter? ) are constant? • Choose some smarter parameter to examine rather than stability and single degree of freedom appearance of the generalized displacements and pitch angle? • Find some reduced order method or sensitivity-based analysis to guide the CFD solution process? Convergence studies? • Work harder at the typical section analysis, using those results to perform temporal convergence? • Spatial convergence / Grid Adaptation for unsteady flows with grid motion: What is the right way? • Unsteady flow modeling: Are there turbulence models appropriate, validated for unsteady flow? • Structure-fluid coupling methodology and timing • We have one result using EDGE that indicates that this doesn’t matter for the EDGE implementation • Is this code (implementation) dependent? Which codes have similar implementation? Different implementation? Aeroelastic Prediction & Validation Technical Working Group

Summary of April (and March) telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon held April 7. No telecon slides. Mini-telecons held to discuss individual data sets in the database and work on fixes. • Next telecon May 5, 11 a. m. East Coast time in U. S. • Details of updated files were included in the March telecon notes • Details of instructions on updating and submitting files were given in March telecom notes • Special session at Sci. Tech Jan 2017: request submitted by Alessandro Scotti to Zahra Sotoudeh (SDTC lead for Sci. Tech). Note that the SDTC chairmanship will turn over this year from Bruce Willis to Chad Hebert. Aeroelastic Prediction & Validation Technical Working Group 38

Summary of February 4, 2016 Telecon • What do we need to do next? • Workshop summary, in brief • Technical issues that we want to discuss • • • Your technical issue that you want to discuss goes here DDES grid now available Flutter boundary exploration with FUN 3 D • Workshop debrief discussion • What would we have liked to be different? • What did we learn? • What is being re-analyzed? (From whom should we be expecting additional results? ) Aeroelastic Prediction & Validation Technical Working Group 39

Summary since Dec telecon • Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ • Last telecon prior to workshop held Dec 3, 2015 11 a. m. • Matrix of results submitted by telecon were reviewed • Discussion panel discussed- panel moderator, participants, title were confirmed • Next telecon March 3, 11 a. m. East Coast time in U. S. • Data submittal spreadsheets fed back to analysis teams with detailed instructions • Workshop held Jan 2 -3, associated with AIAA Sci. Tech conference; organizational aspects provided by Megan Scheidt • Discussion Panel held at Sci. Tech, Jan 5 (Heeg, Raveh, Chwalowski, Righi, Schuster); organizational aspects provided by Joe Slater • Report out to Structural Dynamics Technical Committee (Daniella Raveh, Jan 6) • Special session at Sci. Tech Jan 2017: request submitted by Alessandro Scotti to Zahra Sotoudeh (SDTC lead for Sci. Tech). Note that the SDTC chairmanship will turn over this year from Bruce Willis to Chad Hebert. Aeroelastic Prediction & Validation Technical Working Group 40

Nov 19 telecon summary • Held on Nov 19, 2015 11 a. m. • Next telecon Dec 3, 11 a. m. East Coast time in U. S. • Aviation conference special session approved. 8 abstracts submitted for session • Panel session for Sci. Tech is on the agenda for Tuesday afternoon, Jan 5 • Discussed format, questions, moderator • Status of data submittals to date (Nov 19) • Data submittal Q&A • Brief discussion of workshop agenda Aeroelastic Prediction & Validation Technical Working Group 41

Updated analysis parameter table Aeroelastic Prediction & Validation Technical Working Group 42

October telecon summary • Held on Oct 1, 2015 11 a. m. • Next telecon November, 19 11 a. m. East Coast time in U. S. • Administrative matters • Workshop registration is open on AIAA website • Possible special session at Aviation discussed, interest solicited. 5 teams responded positively on the telecon. • Problems with the telecon number in Italy. Andrea Mannarino, Politecnico di Milano was going to discuss Case 2: Euler Results. Defer until Nov telecon • Analysis results • Case 1 FRFs submitted by 4 teams; comparison plots are included in the Oct telecon slides • Added new results to Case 1 Integrated coefficients plots (included in this file) • Processing discussion: • Process overview and details Aeroelastic Prediction & Validation Technical Working Group 43

September telecon summary • Held on Sept 3, 2015 11 a. m. • Next telecon November, 5 11 a. m. East Coast time in U. S. • Administrative matters • Telecon slides now uploaded to website • Deadline established for declaring participation as an analysis team: Oct 1 • Advertisement blurb submitted to AIAA • Analysis results • Embraer discussed results for Case 1, both steady and forced oscillation FRFs • Comparisons of steady coefficients for Case 1 were presented and discussed. Results separated by turbulence model, grid size and grid source are included in the Sept telecon slides. • Consistent turbulence model study added to the analysis matrix: Case 2: Flutter at Mach 0. 74, 0° angle of attack. For those running RANS analysis, utilize your code’s standard Spalart-Allmaras turbulence model Aeroelastic Prediction & Validation Technical Working Group 44

August telecon summary • Held on August 6, 2015 11 a. m. • Next telecon October 1, 11 a. m. East Coast time in U. S. • Administrative matters • Telecon slides now uploaded to website • Deadline established for declaring participation as an analysis team: Oct 1 • Advertisement blurb submitted to AIAA • Analysis results • Jennifer Heeg showed (July telecon) unforced unsteady results for Case 3 (Mach 0. 85, 5°); Shock motion of ~9% of the chord for the unforced (no excitation) system is very similar using: • EZNSS hybrid DDES (based on k-w SST) , shown by Daniella Raveh on June telecon • FUN 3 D RANS + SA • FUN 3 D URANS + SA • Jennifer Heeg discussed (August telecon) frequency response function (FRF) • Consistent turbulence model study added to the analysis matrix: Case 2: Flutter at Mach 0. 74, 0° angle of attack. For those running RANS analysis, utilize your code’s standard Spalart-Allmaras turbulence model • Discussed the format and content of the panel discussion for Sci. Tech Aeroelastic Prediction & Validation Technical Working Group 45

July telecon summary • Held on July 2, 2015 11 a. m. • Next telecon August 6, 11 a. m. East Coast time in U. S. • Administrative matters • Telecon slides now uploaded to website • Deadline established for declaring participation as an analysis team: Oct 1 • Advertisement blurb submitted to AIAA • Analysis results • Krishna Zore from ANSYS shared results- phase difference relative to experimental data noted; may be definition • Jennifer Heeg showed unforced unsteady results for Case 3 (Mach 0. 85, 5°); Shock motion of ~9% of the chord for the unforced (no excitation) system is very similar using: • EZNSS hybrid DDES (based on k-w SST) , shown by Daniella Raveh on June telecon • FUN 3 D RANS + SA • FUN 3 D URANS + SA • Daniella Raveh from Technion showed results on the June telecon for Case 3: EZNSS RANS solutions showed dependence on the turbulence model • Consistent turbulence model study added to the analysis matrix: Case 2: Flutter at Mach 0. 74, 0° angle of attack. For those running RANS analysis, utilize your code’s standard Spalart-Allmaras turbulence model • Discussed the format and content of the panel discussion for Sci. Tech Aeroelastic Prediction & Validation Technical Working Group 46

June telecon summary • Held on June 11, 2015 11 a. m. • Next telecon July 2, 11 a. m. East Coast time in U. S. • Administrative matters • Analysis team matrix updates continue • Introduced Sci. Tech panel discussion • Analysis results Marcello Righi, Zurich University of Applied Sciences (ZHAW, ZUAS) • Case 1: showed results using Edge and SU 2 • Unforced system shown as both average results from dynamic case and steady analysis • Frequency response functions at forcing frequency & at higher harmonics; showed disagreement in the shock/divot region Daniella Raveh, Technion: • Cases 2: Varied time step size, temporal convergence criteria and turbulence model • • Flutter frequency was slightly lower with a finer mesh; temporal convergence study showed increased damping with decreased time step size; “good enough” declared at time step size of 0. 00024 seconds turbulence model changed the damping Solution hasn’t converged to an oscillatory behavior at 1. 5 seconds (~ 6 cycles); more iterations (global time steps) are needed • Case 3: hybrid DDES shows unsteady flow with shock motion Aeroelastic Prediction & Validation Technical Working Group 47

May telecon summary • Held on May 7, 2015 11 a. m. • Next telecon June 11, 11 a. m. East Coast time in U. S. • Discussed administrative matters • AIAA coordination: Workshop will be held Saturday Jan 2 (3 pm-6 pm) & Sunday Jan 3 (8 am-6 pm) • Workshop process • Workshop agenda • Discussed having a panel / discussion session at Sci. Tech- during the conference week • Analysis team matrix updates continue • Suggested face to face at AIAA Aviation conference- not a lot of anticipated participation • Corrected & updated workshop information from May • Units on stiffness values • Kh = 2637 lb/ft = 219. 75 lb/in = 219. 75 slinch/sec^2 • Ktheta = 2964 ft-lb/rad = 35568 in-lb/rad= 35568 slinch-in^2/s^2/rad • Corrected Reynolds number for Case 1 (Mach 0. 7, 3°) • Rec = 4. 56 x 106; Re = 3. 456 x 106 Aeroelastic Prediction & Validation Technical Working Group 48

AIAA Interactions Approved and signed off by Bruce Willis, Chairman of Structural Dynamics Technical Committee Megan Scheidt, Managing Director of Products and Programs Aeroelastic Prediction & Validation Technical Working Group 49

Envisioned Workshop Process for Analysis Teams (May, 2015) • • Perform analyses Submit results Prepare informal presentations for workshop Sci. Tech 2016 • Ae. PW-2 • • Present results Results comparisons Discussion of results Path forward • Panel discussion? ? ? • Re-analyze • Publish at special sessions of conferences (which conferences? ) • Publish combined journal articles Aeroelastic Prediction & Validation Technical Working Group 50

April telecon summary • • Held on April 2, 2015 11 a. m. Next telecon May 7, 11 a. m. East Coast time in U. S. Updated analysis parameters matrix; uploaded to website Experimental data was added to website List of analysis teams produced Discussion of workshop dates Experimental data reduction showing “divot” in the FRFs to likely be physical • Pawel showed animation of flutter solution at Mach 0. 74 using FUN 3 D Aeroelastic Prediction & Validation Technical Working Group 51

• • • March telecon summary Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ Held on March 12, rather than March 5 (with the usual March daylight savings time issues) Next telecon April 2, 11 a. m. East Coast time in U. S. SU-2 doesn’t have existing FSI capability. (Melike and Dave Schuster to talk about this? ) Block-structured grids from Ae. PW-1 are available, generated by Thorsten Hansen at ANSYS. (Thorsten and Pawel will work together to make those available on the new website. ) • The molecular weight of R-134 a isn’t the same as a standard property table shows (102 g/mol). The value derived using the listed properties is more like 98 g/mol. This is due to the practical issue of gas purity that is achieved in the wind tunnel. The values on the table are from the test data, where the purity was likely 95%’ish. (Pawel will add a line for molecular weight to the analysis parameters table. ) • Add the following to the table of analyses: • • • ATA Engineering (Eric Blades will run Lo. Psi. Chem) AFRL (Rick Graves will run FUN 3 D) Milano Polytechnico (Sergio Ricci will run numerous codes) • Please send comments regarding the distributed slides. In particular, are you okay with the abstract submittal form? • With regard to submitting data to the workshop for comparison: • • Can you provide results in matlab? How do you feel about providing them in a data structure in matlab? • Doublet lattice aeroelastic solution results: • • Bimo and Jen will work to present the results to date at the next telecon We will put the bulk data file, including the aero model and the flutter cards on the web site. This can serve as a basis for those who might want to use correction methods, etc. • Temporal convergence results • • Organizations may not have the resources to perform the temporal convergence study for all grids. It is suggested that this be done for a grid resolution where things look to be spatially converged. Experience at NASA has shown qualitatively different results for the unstructured coarse grid than those observed for the finer grid resolutions. The flutter results at low Mach number (Mach 0. 74) have shown great variation with regard to time step size. The predicted aeroelasticity stability of the system has been shown to be a function of the time step size and the subiteration convergence level. Aeroelastic Prediction & Validation Technical Working Group 52

• • • March telecon summary Website address: http: //nescacademy. nasa. gov/workshops/Ae. PW 2/public/ Held on March 12, rather than March 5 (with the usual March daylight savings time issues) Next telecon April 2, 11 a. m. East Coast time in U. S. SU-2 doesn’t have existing FSI capability. (Melike and Dave Schuster to talk about this? ) Block-structured grids from Ae. PW-1 are available, generated by Thorsten Hansen at ANSYS. (Thorsten and Pawel will work together to make those available on the new website. ) • The molecular weight of R-134 a isn’t the same as a standard property table shows (102 g/mol). The value derived using the listed properties is more like 98 g/mol. This is due to the practical issue of gas purity that is achieved in the wind tunnel. The values on the table are from the test data, where the purity was likely 95%’ish. (Pawel will add a line for molecular weight to the analysis parameters table. ) • Add the following to the table of analyses: • • • ATA Engineering (Eric Blades will run Lo. Psi. Chem) AFRL (Rick Graves will run FUN 3 D) Milano Polytechnico (Sergio Ricci will run numerous codes) • Please send comments regarding the distributed slides. In particular, are you okay with the abstract submittal form? • With regard to submitting data to the workshop for comparison: • • Can you provide results in matlab? How do you feel about providing them in a data structure in matlab? • Doublet lattice aeroelastic solution results: • • Bimo and Jen will work to present the results to date at the next telecon We will put the bulk data file, including the aero model and the flutter cards on the web site. This can serve as a basis for those who might want to use correction methods, etc. • Temporal convergence results • • Organizations may not have the resources to perform the temporal convergence study for all grids. It is suggested that this be done for a grid resolution where things look to be spatially converged. Experience at NASA has shown qualitatively different results for the unstructured coarse grid than those observed for the finer grid resolutions. The flutter results at low Mach number (Mach 0. 74) have shown great variation with regard to time step size. The predicted aeroelasticity stability of the system has been shown to be a function of the time step size and the subiteration convergence level. Aeroelastic Prediction & Validation Technical Working Group 53

Feb Telecon Notes • Attendees list (to be added) • Suggested adding to website: • • Participating teams and matrix with contact information Experimental data (Action item taken by Jen. ) • Request made that the frequency response function information be available in both rectangular form (Re and Im components) as well as in polar (Mag and phase) form. (Action item taken by Jen. ) • Experimental results for Case 1. In the FRF magnitude, there is a sawtooth near the leading edge. What is the source of that? Physical? Sensor issue? (Action item taken by Jen. ) • Grids: structured grids were generated by NASA in plot 3 D format using Pointwise. The gridding guidelines still include the RSW and HIRENASD from Ae. PW-1. Need to revise them so that they are not confusing. Revisit them also with regard to the Reynolds number. • Nonlinear effects and LCO: • • Discussion regarding hysteresis and identification of the neutral stability point Discussion about experimental data sets, including a DLR study on LCO where there were trends with Mach number • Process: • • Think about what questions we are trying to answer How do we tell the organizing committee that we are participating by performing analyses? Is there a website sign up or abstract submittal form that we mail? • Note: following the end of the telecon, as the webex window was closing… it was noted that there were some questions and/or comments on the webex communication window. Apologies for noticing them. The window closed before we could stop it. We are not smart enough to figure out the now-erased questions. Can you ask them again? • Next telecon March 5, 11 a. m. Aeroelastic Prediction & Validation Technical Working Group

Mini-abstract from Ae. PW-1 MRL and USF Contribution to Ae. PW - 1 N. N. Thusiast_ Multielement Research Lab, Mail Stop 000, Happy Forks, VA 00000 email: m. n. thusiast@mrl. gov, (777) 777 -7777 Soar N. Air† University of Southern Flight, Mail Code 98765, Lofty Heights, TX 00000 email: s. n. air@usf. edu, (888) 888 -8888 We intend to participate in the Ae. PW-1, to be held April 21 -22 2012 in Honolulu, HI. We plan to perform the following sets of computations: Configuration 1 – RSW , Steady Case, i. M=. 825, =2 deg Code: RANS-CFD-3 D Grid: Str-Oneto. One-C-v 1 (supplied by Ae. PW-1 committee) Turbulence model: Menter SST Configuration 1 – RSW , Unsteady Case, i. M=. 825, =2 deg, 10 Hz Same as above Configuration 2 – BSCW, Steady case, M=. 85, =5 deg, 10 Hz Same as above Configuration 2 – BSCW, Unteady case, M=. 85, =5 deg, 20 Hz Same as above Configuration 3 - HIRENASD Configuration, steady, M=. 8, Re=7 million, =1. 5 deg Code: RANS-CFD-3 DAe Grid: Str-Oneto. One-C-v 1 (supplied by Ae. PW-1 committee) Turbulence model: S-A We plan to submit our results electronically by the March 20, 2012 deadline to the Ae. PW-1 committee. RANS-CFD-3 DAe is a Reynolds-averaged Navier. Stokes code developed by Et et al. , 1 widely used at the Multielement Research Lab. It is specifically formulated to work on three-element wing configurations. It uses point-matched grids, and is an upwind finite-volume structured code. LES-CFD-3 D is a large-eddy simulation code developed at the University of Southern Flight. 2 It employs 6 th order central differencing in space and 3 rd order temporal differencing, along with 9 th order explicit filtering. References Et, H. , Cet, P. , and Era L. , “Description of RANS-CFD-3 D, ” Journal of Codes, Vol. 6, No. 5, 1994, pp. 5– 21. Author, A. and Author B. , “Description of LES-CFD-3 D, ” Journal of Lengthy Papers, Vol. 9, No. 2, 2008, pp. 22– 1021. _ Corresponding Author. Senior Research Scientist, High Lift Branch. † Professor and Chair, Dept. of Aeronautical Engineering. Aeroelastic Prediction & Validation Technical Working Group 1 of 55

Acknowledgements • Megan Scheidt, AIAA, organizing and coordinating • Joe Slater, Bruce Willis, Dale Pitt, Structural Dynamics TC, sponsorship, coordination, general support • Organizing committee for doing preliminary analysis and preparations. • • • Pawel Chwalowski, NASA Adam Jirasek, FOI Daniella Raveh, Technion Mats Dalenbring, FOI Alessandro Scotti, Pilatus Dave Schuster, NESC, NASA Jennifer Heeg, NASA Analysis team leaders and members Code development teams whose work we have utilized in performing these analyses Projects, programs and companies funding this work Workshop participants for insightful and lively discussions Aeroelastic Prediction & Validation Technical Working Group

Goals in data reduction: (these are plots from Ae. PW-1 data reduction effort for HIRENASD) Aeroelastic Prediction & Validation Technical Working Group