This project is an ongoing effort to improve airfoil efficiency by testing "deturbulation" techniques
on a glider in flight. Progress has been slow because the work is being done with private funding and equipment,
in a club environment.
This work began in 2003 as a cooperative effort by Dr. Sumon Sinha and Jim Hendrix.
However, it split into separate efforts when it became clear that our objectives were not compatible.
Until March 2011, it could only be said that we had demonstrated the viability of a new method of boundary flow control
on wings and similar surfaces. Now, it appears that I have arrived at a simple, cheap, and practical
modification that may offer 15%
improvement on Wortmann wings. Applicability to modern airfoils remains to be seen.
In December 2006, my glider was taken to the legendary Richard H. (Dick) Johnson
for independent testing. Johnson confirmed average improvements of 13% to 18% at 50 knots indicated airspeed.
He measured sink rates manually using his time honored methods.
Johnson summarized his report, with the conclusion that
"the new Sinha Deturbulator could be the first really significant drag-reducing aerodynamic invention
since the development of the now-common laminar-flow airfoils that were developed some 65 years ago."
This method (1) reduces form drag by keeping the detached flow close to the surface,
(2) reduces surface area exposed to laminar skin friction near the front of the wing,
(3) reattaches the flow gently for less energy loss to turbulence and,
(4) detaches the flow again behind the reattachment line to reduce surface area exposed to turbulent skin friction.
On the top surface, this requires a delicate balance of conditions repeat but are not consistent.
For more information, read the Project Summary.
A recent discovery is that merely a properly sized rear-facing step near the leading edge can produce significant performance improvements
consistently. For more on this, see
(Leading-Edge-Tape-Only Performance Measurements).
This appears to be a practical modification for the lower surface.
For an overview and explanation read The Deturbulator Tape (PDF, 687 KB).
Sufficient data now exists to justify funded R&D efforts to
(1) model the modified flow dynamics,
(2) optimize performance characteristics,
(3) develop new airfoils to exploit this technology and
(4) to develop practical applications in aviation, wind power, ground transportation, etc.
The number of people participating in this effort is growing.
If you are an aerodynamicist or merely an interested person you are invited to take part.
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