Thermal simulations and calculations of a thermal gas flow sensor based on thin-film thermopiles are presented using the FEA tool ANSYS/FLOTRAN.The influence of inlet gas flow pitch angle on the sensor output and gas flow is investigated.The results of thermal simulation related to the response of the signal voltage to variations of flow velocity at constant gas temperature are compared with experimental data.The good agreement between calculated and experimental results confirms the proposed two-dimensional thermal model.The thermal model and simulation provide a simple method for the design optimization of gas flow sensors based on thin-film thermopiles.