Abstract:The temperature field and stream field of the twowire spherical sensitive element are calculated by using the finite element method(FEM), and the sensitive mechanism of the sensor is explained and verified. The numerical results and experimental results show that the temperature field and stream field of the twowire spherical sensitive element change with the inclination angle θ.When the inclination of the isotherms is no more symmetrical, the overlap of the high temperature isotherm is reduced; when θ=0°, the average temperature difference of thermal resistance r1 and r2 is ΔT=0,when θ=10°, ΔT=7.31 K, when θ=20°, ΔT =13.64 K. The average sensitivity of ΔT changing with θ is 0.707 K/(°). When the closed spherical cavity is inclined, the average temperature of the thermal resistance wire with high position is higher, θ and ΔT are almost linear relationship; the average relative deviation is 4.5% compared with the measured values.The temperature difference ΔT of thermal resistance r1 and r2 changes with θ ,which causes the thermal resistance r1 and r2 to change, the detection of bridge outputs a unbalanced voltage ΔV corresponding to θ.The proposed method have opened up an effective way for structure optimization and performance improvements of the structure of the flow inclination sensor with twowire spherical sensitive cavity.