Abstract | In this paper, wind tunnel experiment was performed for boundary layer transitioncontrol on a morphing wing. Surface pressure fluctuations weremeasured using Kulite transducersat high sampling rate. A controller, linking the Kulites signals fluctuation to the smart material actuators, is incorporated to the control system, where thesignals are analyzed and the transition location is detected. Several wind tunnel test runs for various Mach numbersand angles of attack were performed in the 6 ×9 ft2 wind tunnel at the Institute for Aerospace Research at the National Research Council of Canada. A rectangular finite aspect ratio wing,having a morphing airfoil cross section due to a flexible skin installed on the upper surface of the wing, was instrumented with sixteen Kulite transducers. The Mach numberwasvaried from 0.2 to 0.3and the angle of attack between -1oand 2o. Unsteady pressure signals were recordedand analyzed and a thorough comparison,in terms of mean pressure coefficientsand their standard deviations, was performedagainst theoretical predictions using the XFoil computational fluid dynamics code. The unsteady pressure signals were analyzed through FFT spectral decomposition for detecting the Tollmien-Schlichting waves frequencies that trigger transition. In addition, infra red measurements were performed to asses the performance of the Kulite transducersin detecting the transition location and serve as an additional validation of the XFoil code in predicting the transition location. |
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