Abstract: The mechanism of frictional heat generation and heat transfer in brush seals was analyzed and a computational fluid dynamics (CFD) model was developed. In the model,the brush was treated as an anisotropic porous region with nonlinear resistance coefficients and the frictional heat as a heat source. The pressure distribution,velocity field and temperature field were obtained and the maximum temperature under various interference and pressure difference conditions were studied. The investigation shows a steep temperature rise in bristle-rotor interface,which diminishes further away in the radial direction; fluid convection and leakage flow affect temperature distribution deeply. The results can be used to guide brush seal geometry design,contact-pair material selection and interference fit.