Theoretical and experimental studies of a surface acoustic wave flow sensor

A novel SAW flow sensor is proposed based on pressure measurement. The relationship between the flow rate and the pressure difference along the flow path is evaluated. The results show a linear relationship between the flow rate and pressure difference, which agrees with the past research results. Strain analysis and FEM simulation show that phase delay depends linearly on the flow rate passing the SAW sensor, whereas SAW frequency decreases linearly upon the increase of flow rate. Phase delay experiment results agree with analysis and simulation, and the frequency change falls in a reasonable range around the predicted curve.