Simulation and testing of a MEMS calorimetric shear-stress sensor

The principle of operation of a new MEMS calorimetric shear-stress sensor is described. The sensor is based on the detection of the thermal wake generated by a heated beam over a cavity. Numerical simulations and wind-tunnel tests are conducted to highlight the effects of the inter-beam distance and the importance of the constant-temperature mode of operation. The calibration of a sensor prototype in a range of ±1.2 Pa of wall shear-stress in air is performed and the sensor's capability to measure the mean and fluctuating wall shear-stress and the flow direction in a separation-bubble flow is demonstrated. Results of reverse-flow intermittency measurements are compared with those obtained with a classical thermal-tuft probe.