MODELING AND CHARACTERIZATION OF THE SENSITIVITY OF A HOT-WIRE PARTICLE VELOCITY SENSOR

Abstract The sensitivity of an innovative micromachined acoustic sensor consisting of four hot-wires is analyzed theoretically and experimentally. An analytical model is presented that describes both the air flow and the temperature profile in and around the probe. The presence of the chip surface in the vicinity of the wires influences the acoustic flow, while also affecting the temperature distribution in the probe. Both effects result into a specific angular dependence of the sensor sensitivity. Acoustic flow measurements are compared with the theory and with numerical simulations on the device,showing good qualitative and quantitative correspondence. Key Words: particle velocity sensor, acoustics, flow sensors, MEMS-modellin