SinhaTech - Sinha Deturbulator Development Progress Reports

Sinha Deturbulator Progress Reports

Progress Articles

6/21/2003	Drag measurement instrumentation
9/17/2003	First successful test of Sinha deturbulator on a glider
10/18/2003	Further drag reductions on Standard Cirrus wing
	A comparison to turbulators
	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)
05/31/2008	Second Parallel Flight - vs. LS3
05/31/2008	Third Parallel Flight - vs. Diana 1

Publications and Presentations

1/9/2006	Sailplane Performance Improvement Using a Flexible Composite Surface Deturbulator - Sinha (PDF, 1174 KB)
6/5/2006	Drag Reduction of Natural Laminar Flow Airfoils with a Flexible Surface Deturbulator - Sinha (PDF, 757 KB)
2/10/2007	Wing Surface Deturbulators - Johnson (PowerPoint, 2140 KB)
2/10/2007	Revolutionary Aerodynamics - Sinha (PDF, 856 KB)

2/10/2007	Two Years on Deturbulated Wings - Hendrix (PowerPoint, 395 KB)
6/26/2007	Optimizing Wing Lift to Drag Ratio Enhancement with Flexible-Wall Turbulence Control - Sinha (PDF, 588 KB)
8/6/2007	Improving Automotive Fuel Efficiency with Deturbulator Tape - Sinha (PDF, 1368 KB)
2/14/2008	Extreme Performance - Hendrix (PowerPoint, 1.4 MB)

Stereolithography used for wind tunnel wing sections (8/31/2004)

Figure 18. Close up of SLA wing surface before finishing

In our search for ways to make accurate wing sections for Dr. Sinha's wind tunnel, we settled on Stereolithography (SLA) as a good way to obtain the correct basic profile. Finishing the surface would be easy after that. We found a prototyping shop in our area that could do SLA and inquired about pricing. After the sticker shock wore off, we realized that the cost became reasonable if we made our wing sections in batches of five or so. So we supplied Vision Engineering with Cad files for five airfoils: Std. Cirrus root, Std. Cirrus tip, NLF0414F, ASW-22BL root and ASW-22BL tip.

Figs. 18 and 19 show the results. Fig. 18 is a close up of the unfinished SLA surface. Fig. 19 is the finished Std. Cirrus root wing section mounted between boundary layer control disks, ready for installation in the wind tunnel. The disks reduce the sidewall bounday layer thickness in the test section of the wind tunnel so that airflow over the wing section is two dimensional except for the outer 3/4".

Jim Hendrix
Oxford Aero Equipment

Figure 19. Finished Std. Cirrus root wing section

Airspeeds shown in graphs are instrument calibrated. The aircraft airspeed system is not calibrated. Errors in the Standard Cirrus static/Pitot system bias the data towards higher speeds. This makes polars seem better than they really are. However, this is not an issue when the purpose is only to show comparitive data on the same glider.

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