Evaluation of Passive Boundary Layer Flow Control Methods for Aero-Optic Mitigation
نویسنده
چکیده
Results of recent experimental measurements of the effect of passive boundary layer flow control method using Large-Eddy Break-Up devices on aero-optical distortions caused by turbulent subsonic boundary layers at a range of trans-sonic speeds are presented. Measurements were performed using a Malley probe to collect instantaneous onedimensional wavefronts with high resolution. Detailed statistical analysis of optical spectra of aero-optical distortions are presented in order to evaluate the effect of modified turbulent structures on optical wavefront fluctuations, and to assess the mitigating aero-optical effect of each flow control method. It was found that a long, at least 1.6 boundary-layer thicknesses, LEBU device, placed at 0.5..0.6 boundary-layer thicknesses away from the wall resulted in significant, up to 33% reduction in overall level of aero-optical distortions. In addition, velocity profiles measured with hot-wires are presented and analyzed in order to investigate how the underlying large-scale flow structure is modified by the LEBU device.
منابع مشابه
Aero-Optical Mitigation of Turbulent Boundary Layers Using Large-Eddy Break-Up Devices
Results of recent experimental measurements of the effect of passive boundary layer flow control method using both singleand multiple-element Large-Eddy Break-Up devices (LEBU) on aero-optical distortions in turbulent subsonic boundary layers at a range of subsonic speeds are presented. Measurements at different locations downstream of LEBU devices were performed using a Malley probe to collect...
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