Project Summary

Since 2003 I have taken numerous drag and performance measurements on Standard Cirrus glider #60 with various deturbulator configurations. Also, I have done a great deal of soaring with deturbulated wings. In addition, independent performance measurements were taken by the legendary Richard H. "Dick" Johnson in December 2006 (see A Flight Test Evaluation Of The Sinha Wing Performance Enhancing Deturbulators). Altogether, these efforts have produced a large body of evidence for performance improvements using the deturbulator flow-control method. Much has been learned about the potential benefits, but much research and engineering remains to be done. Deturbulator Research is committed to encouraging and assisting the efforts of others to understand and use deturbulation methods.

Deturbulator Components

A full deturbulator configuration consists of (1) a thin (.003") deturbulator tape wrapped around the leading edge of the wing that produces a very small referse-facing step as seen by the boundary flow soon after it splits at the stagnation point and (2) a deturbulator panel located at .6 chord on the upper wing surface. More will be said about these below.

Performance with Full Configuration

Because deturbulation on the upper wing surface depends critically of precise control of several variables, consistency is hard to achieve. Thus, flight-to-flight differences are often extremely large. This means that the traditional means of reducing scatter in sink rate measurements by averaging data points obscures real performance changes that reveal the true potential of the deturbulator method. For this reason, it is often necessary to study individual measurements in order to see the true effects of deturbulation. Examining individual measurements is not unreasonable, as long as one keeps in mind that the results are approximate. Confirmation of this may be seen in repeating patterns in Figures 1-3 below.

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