A New Method for Measuring Flow Velocity Using Periodic Heating and the Sensing Characteristics of a Micro Flow Sensor Manufactured by MEMS Technique

In this paper, a new method for measuring flow velocity has been proposed. It adopts periodic heating as an input signal, and flow velocity is deduced from the phase delay of output signal, coming from adjacent temperature sensors. Since this method doesn't use absolute values of the temperature, but only phase delay, it has a strong robustness against possible noise. We have developed a simplified model based on a quasi-steady state of thermal convection in fluid, and compared the model predictions with experimental results. It's found that the model is able to explain the experimental results qualitatively. The proposed method, which makes use of a micro sensor manufactured by MEMS technique, provides a wide dynamic-range of flow velocity measurements with a simple electronic circuit.