[en] The buoyancy term of turbulence model is studied, and modification of the buoyancy model has been carried out. After that, several cases of supercritical flows with heat transfer are calculated and the results are compared with DNS and experiment data in the open literatures. The results show that the modified model can predict the buoyancy term correctly, and thus the calculated wall temperature agrees well with the experimental data and DNS data. In contrast, the wall temperature obtained by the traditional models is much higher than the experimental and DNS data. (authors)