AeroMEMS polyimide based wall double hot-wire sensors for flow separation detection

A polyimide-based MEMS hot-wire sensor featuring two resistors in close proximity (200 μm) has been developed. Combining a flexible printed circuit board and a number of such MEMS wall double hot-wires, a so called hybrid AeroMEMS sensor array is established. Setup of both single double-wire sensor and hybrid array, as well as wind tunnel experiments to determine the position of flow reattachment behind an airfoil are described. Further wind tunnel measurements on a generic two-dimensional model of a high-lift system of an airplane, consisting of a main airfoil and a flap, are presented. Evaluation of the experiments proves that the hybrid sensor array is well capable of detecting near-wall regions of flow separation as well as complete flow separation from the flap. This sensor system permits the detection of small near wall regions of flow separation on this specific aerodynamic configuration which were not detected by other measurement methods.