The flow field in the micro-gap of foil gas bearing is often in the slip zone,even in the transition zone,and there will be some micro-effects,so it is no longer appropriate to use the macro method to study its thermal characteristics.To study the variation law of thermal characteristics in the clearance of gas-lubricated journal bearings under different working conditions,a numerical model of radial bearing clearance heat transfer including viscous heat dissipation was established based on the lattice Boltzmann method.The double distribution function thermal model in the form of total energy was adopted and applied to the body-fitted mesh through finite difference discretization,and the velocity slip and temperature jump boundary conditions were introduced to calculation the gas film temperature distribution in bearing clearance under different parameters by numerical simulation.The effects of different Eckert( Ec ) numbers,eccentricity ratios,rotational speed conditions,and temperature jump on viscous heat dissipation were analyzed.The results show that when the Ec number,eccentricity ratio,and rotational speed increase,the maximum temperature of the gas film increases,and the temperature jump on both sides increases.The neglect of the temperature jump effect will lead to different degrees of underestimation of the viscous heat dissipation.