1 / 31

Extreme Performance

Extreme Performance. Jim Hendrix Oxford, Mississippi. How to Receive This Lecture. Not as conjecture Not as wild eyed speculation Not as extrapolated theory ______________________________________________________________________ Think of it as a history lesson!

bebe
Download Presentation

Extreme Performance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Extreme Performance Jim Hendrix Oxford, Mississippi

  2. How to Receive This Lecture • Not as conjecture • Not as wild eyed speculation • Not as extrapolated theory ______________________________________________________________________ • Think of it as a history lesson! • “No brag, just fact.” – Will Sonnet

  3. A Word About Objectivity “If you haven’t spoken a number, you haven’t said anything at all.”– anonymous (Does anyone know the source?)

  4. 25% Was EasyOctober - December 2006Cherry Valley - Caddo Mills

  5. Caddo Mills 12/2006 - Day 1 Johnson Baird Johnson Baird

  6. Caddo Mills 12/2006 - Day 2 Johnson Baird

  7. Caddo Mills 12/2006 Clean-Wing Flights

  8. Symmetries About 50 kts

  9. Worst Case Johnson Errors

  10. Deturbulator DifferencesJohnson 12/2006 Hendrix 12/2007

  11. First Flight with New DeturbulatorsOil-Flow tests revealed problem.

  12. The Smoking GunJohnson Flight #3 RepeatedOne year later – New Deturbulator – Heavier Pilot

  13. How is this kind ofperformance possible? • The objective was to coerce slightly detached flow over the entire suction side of the wing! • Primarily, two modifications accomplish this: • Passive tape around the leading edge • Deturbulator tape at the transition reattach point • Unexpected benefit...detached flow on the pressure side too.

  14. Imagine a Virtual Wing Flow detaches from surface at step-down near LE.Flow accelerates due to loss of skin friction.Faster flow resists curving with wing camber.Flow hits deturbulator at grazing angle.Modified turbulent flow remains detached to TE.

  15. Anatomy of a Transition Bubble Greg Cole Imagine this flattened down and starting at the leading edge. Also, imagine the trailing flow slightly detached and less turbulent. What would happen to skin friction? ... Trailing turbulence? How important is skin friction in attached laminar flow? Is attached laminar flow the best we can do?

  16. Oil-Flow Image of Transition Bubble on Std. Cirrus Wing

  17. Oil-Flow Image of DeturbulatedFlow - Forward Top Surface

  18. Oil-Flow Image of DeturbulatedFlow - Entire Top Surface

  19. Flow Lifting Away from Surface Behind Deturbulator

  20. Close-Up of Deturbulated FlowBehind Deturbulator

  21. Bonus Benefit - Pressure SideSlightly Detached Flow

  22. Normal Pressure Side Oil-Flow -Early Deturbulator Doing Its Thing

  23. All Over the Pressure Side • Where is the bubble? • Where is the zig-zag turbulator? • Where is the flow lifting off the surface? • Where is the flow returning to the surface?

  24. Something Curious at 50 KnotsJohnson 12/2006 Hendrix 12/2007

  25. Sliding Average at 50 KnotsFour Second Intervals

  26. Sliding Average L/DFour-Second IntervalsTwo Flights

  27. Are We There Yet?Second 50 kt Speed Run – 12/1/07

  28. Now, what about this one?Jeff Baird, Flight 4, Caddo Mills, 12/13/2006

  29. New Team Member Jari Hyvärinen, of Sweden, has joined our team. He is modeling deturbulator operation using his own Linflow software that quickly simulates both large and MEMS scale aeroelastic processes. www.linflow.us

  30. Conclusions • Extreme performance has been demonstrated! • Sufficient evidence exists to convince anyone willing to seriously consider the evidence. Flight logs are available on the web at www.sinhatech.com. • Sumon Sinha disserves recognition as the first to envision the possibility and for making it happen. • Much research and development work is needed to fully understand detached, deturbulated flow and to make it a practical reality.

  31. A Standing Offer My glider is available for independent testing by anyone recognized internationally for expertise in evaluating sailplane performance. • Conditions: • Must cover expenses. • Must publish only IGC-log corroborated flight data. • Must fly sufficient flights in conditions suitable for deturbulator performance.

More Related