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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 (5/6/2006)

Dr. Sinha presented a paper entitled Drag Reduction of Natural Laminar Flow Airfoils with a Flexible Surface Deturbulator at the 3rd AIAA Flow Control Conference on June 5-8, 2006 in San Francisco, California. This paper gives an overview of Dr. Sinha's flight test results. The abstract reads:

A flexible composite surface deturbulator (FCSD) has been developed in order to stabilize large extents of thin separated flow over aerodynamic surfaces through passive interactions with a streamwise varying pressure gradient boundary layer flow. This accelerates the external flow since skin friction is mitigated, while attenuating turbulent dissipation in the separated region. In this study this effect has been used to reduce drag and increase lift of natural laminar flow airfoils at low Mach numbers with Reynolds numbers ranging from 3x105, which is typical of long endurance unmanned aerial vehicles, to 6x106 typical of many general aviation aircraft. Wing profile drag reduction of 10-20% was observed in high-Re flight tests with a NLF-0414F wing. Low-Re wind tunnel measurements on the NLF-0414F have shown a profile drag reduction of 60-80% including a 45% reduction in pressure drag, along with a 12% increase in section lift coefficient. This doubled the L/D from 12.5 to 25.7. A full-span upper surface FCSD treatment of an earlier generation Wortmann FX-S-02196 natural laminar flow wing indicated a 5-20% increase in total aircraft L/D over the range of flyable airspeeds.

For a PDF copy of the full paper, click AIAA-2006-3030-245.


© Copyright 2003-2008 Jim Hendrix