Optimization of two-element flow sensors by numerical simulations

Simulation and measurement results are presented for a two-element boundary layer flow sensor fabricated using silicon semiconductor processing and micromachining technologies. The sensor is located on a thermally isolated membrane and utilizes platinum-based resistive heating and sensing elements. Device optimization is based on quasi-3D numerical solutions of the electrothermal equations governing heat transport. We investigate the effects of geometrical non-idealities on the output response and offset. The results corroborate well with measurement data for a large range of operating voltages and flow velocities.