Abstract: Numerical investigations on flow and heat transfer were conducted for transcritical pressure fluid. A three-dimensional numerical method was developed by modeling upward water in a uniformly heated tube with inside diameter of 6.07 cm. Numerical results based on the buoyancy-corrected k-epsilon turbulence model are in good agreement with the experimental data under normal heat transfer conditions. The flow pattern and wall temperature distribution indicate heat transfer deterioration when temperature range experiences the pseudocritical point. Buoyancy plays a significant role in the occurrence of heat transfer impairment, though clear discrepancy is found mainly due to physical model’s inadequate prediction. Further recommendations were made for numerical applications to transcritical flow and heat transfer.