Modelling and Simulation of a Thermal Flow Sensor for Determining the Flow Speed and Thermal Properties of Binary Gas Mixtures

Abstract A thermal flow sensor has been reported to measure simultaneously the thermal conductivity and flow speed of binary gas mixtures. It features low power consumption and a simple geometry. In this work, by means of 3D modelling and numerical simulations it is shown that the volumetric heat capacity of gas mixtures can also be detected by evaluating the heater's temperature of the sensor under flowing conditions. As a result, for those binary gas mixtures with similar thermal conductivity but different volumetric heat capacity, such as CO 2 -Ar, the gas concentration can also be determined with a high accuracy.