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Sinha Deturbulator Progress Reports

Progress Articles
9/17/2003 First successful test of Sinha deturbulator on a glider
10/18/2003 Further drag reductions on Standard Cirrus wing
  Baseline polar for performance testing
2/8/2004 Progress Report: SSA Convention in Atlanta
2/28/2004 First outer-span test
5/27/2004 Wind tunnel goes into operation
8/31/2004 Stereolithography used for wind tunnel wing sections
12/3/2004 First success on upper surface of Standard Cirrus wing
12/12/2004 More success on upper surface of Standard Cirrus wing
2/18/2005 First Sink-Rate Measurement
(revised 3/13/2005)
2/26/2005 Second Sink-Rate Measurement: Some Encouraging Data
3/19/2005 First Parallel Flight - vs. ASW-28
3/19/2005 Measurements with Full Top Surface Deturbulation
9/12/2005 A Performance Endurance Issue
10/29/2005 It’s Deturbulation Time Again
1/9/2006 Paper Presented at AAIA Annual Conference
2/3/2006 Talk Presented at SSA Annual Convention
5/6/2006 Paper Presented at AAIA Flow Control Conference
7/1/2006 Notes on Endurance and the Temperature/Humidity Issue
10/21/2006 Measurements Show 20% Improvement!
(revised 1/3/07)
12/13/2006 Deturbulator Performance Confirmed!
1/2/2007 Calibrated Airspeeds
12/13/2006 Summary of Johnson Flight Test
(revised 2/10/2007)
12/13/2006 Details of Johnson Flight Test
(revised 12/26/2007)
12/01/2007 Johnson Effect Confirmed
(revised 12/26/2007)
06/7/2008 Third Parallel Flight - vs. Diana 1
(revised 8/3/2008)

Publications and Presentations
1/2006 Sailplane Performance Improvement Using a Flexible Composite Surface Deturbulator - Sinha
(PDF, 1174 KB)
6/2006 Drag Reduction of Natural Laminar Flow Airfoils with a Flexible Surface Deturbulator - Sinha
(PDF, 757 KB)
2/2007 Wing Surface Deturbulators - Johnson
(PowerPoint, 2140 KB)
2/2007 Revolutionary Aerodynamics - Sinha
(PDF, 856 KB)
6/2007 Optimizing Wing Lift to Drag Ratio Enhancement with Flexible-Wall Turbulence Control - Sinha
(PDF, 588 KB)
8/2007 Improving Automotive Fuel Efficiency with Deturbulator Tape - Sinha
(PDF, 1368 KB)


Paper Presented at AIAA Conference (1/9/2006)

Dr. Sinha presented a paper entitled Sailplane Performance Improvement Using a Flexible Composite Surface Deturbulator at the 44th American Institute of Aeronautics and Astronautics Aerospace Sciences Meeting and Exhibit on January 9-12, 2006 in Reno, Nevada. This paper gives an in-depth look at Dr. Sinha's deturbulator research over the last three years using Standard Cirrus #60 as a test vehicle. The abstract reads:

A 5 to 20% increase in the glide ratio of a Standard Cirrus sailplane was observed across its flyable airspeed range by treating 60-100% of the span of the wing upper surface with a Flexible Composite Surface Deturbulator (FCSD) tape. The compliant surface layer of an appropriately positioned narrow FCSD strip undergoes sub-micron scale constrained mode flow-induced oscillations. This encourages the formation of a stable thin and long separation bubble like flow structure in non-zero pressure gradient boundary layers by delaying the breakdown of the shear layer separating the aforementioned bubble from the inviscid external flow. As a result, wind-tunnel tests showed the external flow is accelerated increasing lift, while skin friction is mitigated. This was confirmed by a reduction of the sailplane’s induced and parasitic drag components with extended span FCSD treatment. Furthermore, a parallel flight with a higher performance ASW-28 sailplane yielded results that corroborate these measurements.

For a PDF copy of the full paper, click AIAA 2006-447.




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