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Takes Away Turbulence

Engineering Solutions for Tomorrow's problems Today.

Dr. Sumon K. Sinha has developed a Flexible Composite Surface Deturbulator (FCSD) tape, that effectively reduces drag from air flow over surfaces. Although development is proceeding, Dr. Sinha's deturbulator has already produced 20% better performance in aircraft test flights.

Who is Dick Johnson?
Testing has been done independently by Dick Johnson, recognized internationally for his flight test evaluations of sailplanes since 1960. In his report (PDF) on the first deturbulated aircraft (Standard Cirrus, serial numbmber 60, tested 12/2006) Mr. Johnson said: ” 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 new technology may be used to improve the efficiency of virtually any kind of body that moves through the air, most notably aircraft and motor vehicles. Tests on a passenger van that was only partially deturbulated have yielded 10-15% better gas mileage, corresponding to $300-$500 in annual fuel savings, assuming $3.00/gal and 15,000 miles per year average driving.

Testing on semi-tractor-trailer rigs is underway. Savings between 4% and 10% overall, including idle periods, are indicated by data taken on a rig traveling between Louisiana and Florida.

In the aircraft application, skin friction and turbulent energy are both reduced, yielding less drag and more lift. In the motor vehicle application, turbulent mixing in the wake is reduced, producing a virtual boat tail effect to reduce the drag force.

This technology is based on existing and pending U.S. and international patents by Dr. Sinha.

Research Grants
SinhaTech has obtained competitively awarded R&D funding for this work from NASA and NSF. These have culminated in developing the Deturbulator technology to a point where SinhaTech can offer it for beta testing on automobiles and tractor-trailer rigs.


  • Sinha, S. and Sinha, S., "A METHOD FOR REDUCING DRAG OF SLENDER OBJECTS" (U.S. Provisional Patent Application, March 2005).

Johnson Flight Test Report (PDF)

2007 SSA Convention

Semi-Tractor Trailer Rigs

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)

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)

Email Group
To follow developments in this project, you may subscribe to the SinhaTech Group at Google. Notices will be issued to every subscriber whenever significant progress occurs. They will refer you to this web site where full details can be found on the Progress page.

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News Archive

June 7, 2008

Deturbulated 38 Year Old Glider Matches 2005 Model
On this date, Jim Hendrix flew his deturbulated, 38 year old Standard Cirrus glider against a 2005 Diana 1 that performs with the best gliders available today. For 20 minutes the flew in formation and matched sink rates from beginning to end. This was a remarkable demonstration of the capabilities of deturbulator flow control in real world flying conditions.   (more)

February 14, 2008

Hendrix Speaks in Albuquerque
Jim Hendrix presented the case for extreme performance at the 2008 SSA Convention in Albuquerque. He presented data showing that Dick Johnson flew at 100:0 for 1.2 minutes. He also presented oil flow images confirming the existence of slightly detached flow that eliminates most of the parasitic drag from both wing surfaces.   (PowerPoint Slides)

December 1, 2007

Johnson Effect Confirmed
The third test flight by Dick Johnson in Caddo Mills, Texas, on 12/13/2006 produced such extortionary results that Dick threw it out of his analysis and no one had a mind to give it a second thought. For three months, I studied that and other "anomalies" in the Johnson data, then argued that they were real. Now, Johnson's third flight has been duplicated! On Saturday, 12/1/07, the same glider, with redesigned deturbulators, essentially duplicated Johnson's third flight. His best L/D was an astounding 64:1, a 90% increase. The new measurement was 56:1, a 67% increase. Unbelievable as this seems, these figures are consistent with Dr. Sinha's objective and now the reality of this achievement can no longer be ignored. Extreme performance is both possible and repeatable!   (more)

June 25-28, 2007

Sinha Paper presented at 18th AIAA Computational Fluid Dynamics Conference
Dr. Sinha presented a paper titled Optimizing Wing Lift to Drag Ratio Enhancement with Flexible-Wall Turbulence Control at the 18th AIAA Computational Fluid Dynamics Conference in Miami, Florida. In this paper he reveals fully the intended flow-surface interaction of his Deturbulator and the revolutionary efficiencies that can be achieved by creating an edge-to-edge "slip layer" that essentially eliminates viscous flow losses.   (Read Paper (PDF))

May-June, 2007

Johnson Flight Test Evaluation Published in Soaring Magazines
The Johnson flight test evaluation of the first deturbulated aircraft has been published in two magazines: Soaring (May, 2007), published by the Soaring Society of America, and Sailplane & Gliding (June-July, 2007), published by the British Gliding Association.   (Soaring Magazine Article (PDF))

March 6, 2007

Deturbulator Kits to be Available for Gliders
Dr. Sinha had decided to provide prototype Deturbulator kits to sailplane owners are eager to give it a try. A unique kit will be developed for each glider type. It will include materials and instructions as well as procedures for testing the performance of your glider.   (more)

February 10, 2007

Dick Johnson Presents Flight Test Evaluation at SSA Convention
Dick Johnson presented the results of his flight test evaluation of Jim Hendrix' Standard Cirrus glider with Sinha Deturbulators. Dr. Sinha also spoke, describing how deturbulators work and answering questions from an enthusiastic crowd. Later, Jim Hendrix shared his experiences, flying a deturbulated aircraft, with visiters at the detrubulated SparrowHawk glider in the exhibition hall. PowerPoint files of the presentations may be downloaded from the following links:

December 13, 2006

Deturbulator Performance Confirmed!
The day we have anticipated for three years has arrived. Although the consistency issues reported earlier have not been solved in practice, on the strength of two recent flights we felt that the time was right for independent verification of our claims. The gamble paid off.   (more)

September 27, 2006

Measurements Show 20% Improvement!
Last fall we reported a return of performance with the arrival of cool, dry air. This year it happened again. Two flights on 9/27 and 10/21 in excellent testing conditions indicate a 25% performance improvement for the Standard Cirrus glider that we have been testing. Furthermore, the data illustrate that large changes in performance can result from very small changes in the deturbulator construction and configuration.   (more)

February 3, 2006

Talk Presented at SSA Convention
Dr. Sinha presented a talk entitled Revolutionary Aerodynamics at the 2006 SSA Convention in Arlington, TX. He spoke to a packed room of interested people, describing his approach to improving wing performance by reducing the skin friction component of boundary flow and increasing lift. Dr. Sinha described his work in a non-mathematical way, while showing considerable amounts of wind tunnel and flight data.   (more)

January 9, 2006

Paper Presented at AIAA Conference
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.   (more)

October 29, 2005

It's Deturbulation Time Again
In this report, we provide an inside look at several polar measurements that we made in the process of configuring the deturbulator on Standard Cirrus #60 from early spring to fall this year. We had encountered a loss of performance with the arrival of summer weather. We have worked hard to understand this and we think we know what is happening. Meanwhile, with the arrival of fall weather the deturbulator perked up again and now is now performing as before.   (more)

March 19, 2005

First Parallel Flight Evaluation
On March 19, an opportunity presented itself to directly compare the cruising performance of our partially deturbulated, 35 year old Standard Cirrus glider to an ASW-28, a state-of-the-art standard class ship. The Standard Cirrus is a first generation fiberglass sailplane with an out-of-date Wortmann wing. Whereas, the ASW-28 represents the latest in laminar wing technology, not to mention a low drag fuselage and empennage. The gliders were flown side-by-side for 6 miles at 92 miles per hour. The outcome was a surprising close run.   (more)

February 26, 2005

Second Sink-Rate Measurement
On February 18, we began taking data with an appreciable amount of deturbulator on the wings of Standard Cirrus #60. The first flight was in poor conditions for measuring sink rates; however, the second flight, on February 26, was in much better conditions and the data suggest good things to come.   (more)

December 3, 2004

First Success on Upper Surface of Standard Cirrus Wing
December 3, 2004 was another very good day for the Sinha project. After working months to resolve problems with FCSD on the top surface of the Standard Cirrus wing, we finally realized success. Furthermore, we did this at two widely separated wing stations with similar results, indicating that we are beginning to achieve the consistency we seek.   (more)

August 31, 2004

Stereolithography Used for Wind Tunnel Wing Sections
In our search for ways to make accurate wing sections for Dr. Sinha's wind tunnel, we settled on Stereolithography (SLA) as the means for obtaining the correct basic profile.   (more)

May 27, 2004

Wind Tunnel Goes Into Operation
This month, Dr. Sinha finished construction of a wind tunnel that will be used to advance work on the deturbulator project. He is proceeding to measure the aerodynamic characteristics of this new tool and to use it in taking data for his NASA Langley project. Later, it will be used to study issues related to manufacturing SinhaFCSD and applying it to various aircraft wings.   (more)

February 28, 2004

Outer-Span Test on Standard Cirrus Wing
The inner panel of a Standard Cirrus wing is a transition zone from the Wortmann FX S 02-196 airfoil to the Wortmann FX 66-17 A II-182. Our first drag test on the outer airfoil was done on February 28, 2004. The results were much like the first drag test, but more exagerated, with drag reductions falling off at low speeds, but improving as speeds increased.   (more)

October 18, 2003

Second Successful Test of Sinha Deturbulator on a Glider
On October 18 a flight test yielded two positive outcomes. First, the drag reductions from the first glider test were essentially doubled at airspeeds over 70 kts and greatly improved below 50 kts.   (more)

September 17, 2003

First Successful Test of Sinha Deturbulator on a Glider
On this date, Dr. Sinha tested his deturbulator for the first time on a glider. Previously, he had measured velocity profile changes on a powered aircraft with a laminar flow wing. The glider test used a Johnson style drag probe. Tests were conducted with the lower surface clean and with a 24 inch length of Sinha Deturbulator. The greatest improvement was 19% from 55 to 60 kts. At lower speeds, it fell off to a few percent at 40 kts, and at higher speeds it held steady at 10% to 12%.   (more)


© Copyright 2003-2008 Jim Hendrix