High temperature gradient micro-sensors for skin-friction measurement in flow control applications

Robust micro machined high temperature gradient calorimetric (HTGC) transducers were designed and developed for flow separation control. Based on thermal principle, the transducers measure the amplitude and the sign of skin friction, making them particularly useful for flow separation detection. A set of 12 calorimetric micro-sensors along with miniaturized electronics was implemented on a flap model also equipped with pulsed jets. Flow control experiments were successfully conducted as the natural separation occurring on the model was detected by the micro sensors network and controlled by pulsed jet actuation. Ongoing work concerns the realization of closed-loop flow control experiments using the micro-sensors for feedback.