Characterization of a surface mount hot-film sensor using an open-jet unsteady flow wind tunnel

Hot-film sensors are used for a variety of applications such as measuring wind speed, temperature, and wall shear stress. The characterization of these sensors and their driving circuits is vital for determining their viability in the field, specifically in applications which may contain higher frequency flow events such as gusts as well as with separation detection in turbulent flow. An open-jet, unsteady-flow wind tunnel is used to evaluate the time response and dynamic range of a hot film sensor, where the tunnel can simulate both a velocity impulse as well as periodic input at varying wind speeds. The hot-film is located downstream of the wind tunnel outlet and is surface mounted to a flat plate, which is able to be pitched. Testing at field relevant conditions will be achieved by matching a range of reduced frequencies as expected in the field. Hot-film sensor response will be validated using two methods: pressure taps and particle image velocimetry.