Large eddy simulation of supercritical heat transfer to hydrocarbon fuel
In this article, a large eddy simulation (LES) method for the heat transfer of the hydrocarbon fuel flowing through the uniformly heated miniature round pipe at supercritical pressure has been formulated and validated. The four species surrogate model was used to simulate the real thermophysical properties of the fuel. Validation of the developed LES model was carried out through comparisons of the wall temperature and pressure drop with available experimental data and other turbulence model results. Results show that the LES gave the best prediction. Further calculations based on the proposed LES for three cases including subcritical, transcritical and supercritical temperature ranges were numerically investigated in a systematic manner. It was found that the entrance effect occurred among the subcritical, transcritical and supercritical temperature cases that caused by the developing thermal boundary layer. The significant variation of the thermophysical properties near the pseudo-critical temperature would weaken the heat transfer in the transcritical case where the velocity fluctuation affected more on turbulent heat transfer than the temperature fluctuation did.