Fluid Dynamics Challenges in Flight Mechanics WG

For AIAA FD/APA TC Joint Working Group meeting San Antonio, June 21st, 2009

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Topics

• Objective and Approach• After the White Paper – formation of Working Group• Outline JWG plan• San Antonio 2009 Invited Session

Interesting Topics by Speakers from Industry and Government

• Orlando 2010 focal topics Transonic SWBLI Smooth-surface separation Working up workshop definitions/protocols

• Work to be done by JWG before Orlando 2010

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Objective• Identify (and try to close) gaps in flight mechanics (pitch-up, buffet, wing-drop, etc.) CFD

prediction capability based on relevant fluid dynamic phenomena- Relate flight mechanics issues to fluid mechanics responsible for handling issues (e.g., transition,

shock/boundary-layer interaction, separation, unsteadiness, etc.)- Not focused on a single vehicle geometry

Approach• Produce White Paper to identify specific flow phenomena which have problematic

consequences for the flying qualities of aircraft • Develop Workshop(s) (with specific geometries) to evaluate CFD predictions and define

needs for additional experimental data where necessary• Joint effort between APA and other TC’s (FD, AFM, and Flight Test) as well as

Academia. Plan to coordinate with RTO on fundamental issues

Fluid Dynamics Challenges in Flight Mechanics

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After the White Paper – formation of Working Group

• White Paper developed by APA sub-TC (Vehicle Aerodynamics) “Taxonomy of Flight Mechanics Issues for Aircraft, and underlying Fluid-Dynamics

Phenomena”, AIAA-2009-0744. Presented at Orlando 2009

• Well-received by stakeholders Industry representatives on APA/FD TCs Government representatives and budget holders (AFRL/NASA) AIAA Public Policy team – suggest development into a position paper

• Working group inaugurated at Orlando Members from AFM, APA and FD TCs

– Need to ensure balanced team Additional members co-opted as necessary

– Required knowledge base/skill set will evolve through the life of the working group Approximately fortnightly conference call to progress agenda

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Current Working Group Membership (May 2009)

• AFM TC Ashok Gopalarathnam (NCSU)

• APA TC Eric Charlton (Lockheed Martin)* Stephen McParlin (QinetiQ) Robert Tramel (Kord technologies) Paul Vijgen (Boeing)*

• FD TC Mark Glauser (Syracuse University) Michael Ol (AFRL) Carl Tilmann (AFRL)*

• Others Mike Fremaux (NASA) Charles Hirsch (Ercoftac) Rich Wahls (NASA)*rotated off TC, still on WG

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Outline plan for Working Group (1)

• Working Groups are expected to have a three-year life and a clear set of deliverables.

• In year 1: Publication of White Paper (Orlando 2009) First invited session to expound issues (San Antonio 2009)

• In year 2: Focus on specific flow phenomena

– Transonic SWBLI– Smooth-surface separations

Invited sessions covering experimental knowledge base for focus areas (Orlando 2010)

Definition of experimental basis for workshops (Chicago 2010) Session on modeling of causative flow phenomena in CFD?

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Outline plan for Working Group (2)

• In year 3: Publish statement on postulated causative flow physics for use by

workshop participants (by Orlando 2011) Release test case geometry and flow conditions (Orlando 2011) Have halfway workshop session(s) in Hawaii 2011 Final workshop and results targeted ASM 2012

• Effort needed: Definition of experimental data sets (need FD lead) Agree methodology for comparing CFD results Agree how to test incremental effect of new physics in CFD JWG can benefit from logistic experiences of Drag Workshops

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San Antonio 2009 Invited Session

• Thursday morning June 25, 08:00-11:30, have excellent speakers and topics:

1. Atlee Cunningham, LM Fort Worth, “Real-life adventures with unsteady aerodynamics”

2. Jerry Jenkins, AFRL, “Nonlinear and time-dependent aerodynamic characteristics: Implications for testing and flight mechanics analysis”

3. Mike Fremaux, NASA Langley, “NASA COMSAC Project: Lessons Learned”

4. Dan Vicroy, NASA Langley, “Overview of RTO AVT-161 Assessment of Stability and Control Prediction Methods for NATO Air and Sea Vehicles”

5. Open discussion forum • WG to meet after session to review feedback and programme

• Audience participation/buy-in sought

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Orlando ASM 2010 – focal topics of invited sessions

• Identifying/firming up on invited speakers• Transonic SWBLI

Holger Babinsky/Piotr Doerffer TBD from Boeing Commercial on buffet

• Smooth-surface separation Murray Tobak, NASA Ames (retd.) Jim Luckring, NASA Langley (?) Tony Hutton, Airbus (?)

• Suggestions for possible further speakers Frank Lynch (Douglas, retired) Joe Chambers (NASA Langley, retired) ONERA person on buffet

• Use “information triad” as a basis to categorize papers? Suggest FD TC (Mark Glauser et al.) incorporate into the structure

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Tasks for consideration before/at Orlando ASM 2010 (1)

• We want to identify the primary causative fluids phenomena Ensure these are modeled in CFD Identify useful empiricisms where appropriate How do we disseminate this information?

• Where are there gaps in understanding? Review existing experimental data sets Where are there known discrepancies between CFD and

experiment Make case for ‘building block’ experiments as gap fillers

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Tasks for consideration before/at Orlando ASM 2010 (2)

• “Unfinished business” Public Policy aspects Develop the White Paper into a AIAA position statement ? Plan is to meet with Jim Keenan in San Antonio and find out whether White

Paper could be the basis for AIAA position statement – (format, requirements, customer, approval chain, sign-off)

• Copies of oral presentations at JWG Special Sessions Need to agree on what to do with copies of oral presentation PPTs Recommend to request authors/presenters that at least a copy of their PPT

is allowed to be available within Joint Working group for planning and coordination.

Can we put presentations on JWG sharepoint ? What is AIAA policy ?

• Further develop active participation from AFM and Flight Test TC’s

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Possible Joint WG Publications after 2009 White Paper

• White paper (AIAA-2009-0744) addressed several topics. Paper could provide basis for follow-on paper(s) developed by Joint WG members Further develop postulated causative flow physics for specific

relevant flight mechanical topics– Examples of practical issues (“case studies”)

Summary (by WG members) of oral papers presented in San Antonio and Orlando Special Sessions

Publication by Special Session authors Introductions to Workshop

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Need to Populate AIAA SharePoint for JWG activities

• https://info.aiaa.org/tac/ASG/APATC/default.aspx• Recommend (restricted-access) folder for JWG

members• Can we use this Sharepoint in 2010+ for workshop test

cases ?• Jim Guglielmo has suggested a distinct WG site on the

AIAA server. He can set up a site, but we need to decide how to run it. Any volunteers?

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Need to identify focal points within JWG

• Maintain Sharepoint site.• Public policy version of White Paper.• Session chair to organise process for Transonic SWBLI.• Session chair to organise Smooth Surface Separation.

I can do this one. Need volunteers for others [SMcP]

• Liaise with NASA on RTO and relevant special publications.

• Start defining possible cases for workshops.• Recruitment from new TC members (esp. FD)

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Manoeuvre limits for combat aircraft