Flow reattachment point detection via thermal sensors - PIVevaluation

Abstract Recent advances in flow control have the potential for significant impact on the engineering design. Fluidic flow control is a method for altering flows over aerodynamic surfaces which does not rely upon altering the physical shape of the surface (typically through moving control surfaces such as flaps). The steady air flow along a basic geometry of a backward facing step is used to study the alterations of the resulting recirculation area ether spontaneously or by applying pulsating fluid injection below the edge of the step as control actuator. The PIV method is used to monitor the velocity field and determine the reattachment point. Applying flow sensors based on hot wire anemometry on the bottom wall boundary it is possible to estimate parameters such as the recirculation length or even the region of intense turbulent activity as compared and verified by the PIV. Preliminary measurements by thermal sensors reveals fingerprints of the reattachment zone applying time-frequency analysis.