A static turbine flow meter with a micromachined silicon torque sensor

A new class of flow sensors is introduced where a static turbine converts the volume flow into a torque. In contrast to conventional turbine meters, the wheel does not rotate and consequently it is not sensitive to bearing friction and wear that a rotating wheel experiences. The sensor performance has been evaluated for different blade lengths and blade angles and a model is given to predict the influence of these parameters. Optimization of the wheel can be done in terms of maximizing the sensitivity/pressure-loss ratio. The most efficient wheel in this analysis has a blade length of 2.7 mm and a blade angle of 30/spl deg/ giving a sensitivity of 4.0 /spl mu/V/V/(1/min) when measured using a new silicon torque sensor design.