Extreme Performance

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Extreme Performance
Jim Hendrix Oxford, Mississippi

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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

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A Word About Objectivity

• If you havent spoken a number, you havent said
  anything at all. anonymous
• (Does anyone know the source?)

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25 Was EasyOctober - December 2006Cherry
Valley - Caddo Mills
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Caddo Mills 12/2006 - Day 1
Johnson
Baird
Johnson
Baird
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Caddo Mills 12/2006 - Day 2
Johnson
Baird
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Caddo Mills 12/2006 Clean-Wing Flights
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Symmetries About 50 kts
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Worst Case Johnson Errors
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Deturbulator DifferencesJohnson 12/2006
Hendrix 12/2007
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First Flight with New DeturbulatorsOil-Flow
tests revealed problem.
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The Smoking GunJohnson Flight 3 RepeatedOne
year later New Deturbulator Heavier Pilot
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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 suction
  side too.

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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.
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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?
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Oil-Flow Image of Transition Bubble on Std.
Cirrus Wing
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Oil-Flow Image of DeturbulatedFlow - Forward Top
Surface
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Oil-Flow Image of DeturbulatedFlow - Entire Top
Surface
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Flow Lifting Away from Surface Behind Deturbulator
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Close-Up of Deturbulated FlowBehind Deturbulator
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Bonus Benefit - Pressure SideSlightly Detached
Flow
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Normal Pressure Side Oil-Flow -Early
Deturbulator Doing Its Thing
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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?

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Something Curious at 50 KnotsJohnson 12/2006
Hendrix 12/2007
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Sliding Average at 50 KnotsFour Second Intervals
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Sliding Average L/DFour-Second IntervalsTwo
Flights
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Are We There Yet?Second 50 kt Speed Run 12/1/07
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Now, what about this one?Jeff Baird, Flight 4,
Caddo Mills, 12/13/2006
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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

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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.

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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.