关键词: 低温甲烷;超临界压力;对流换热;数值模拟

Abstract: A numerical investigation,incorporating an accurate estimation of the thermodynamic and transport properties of methane,was systematically conducted for elucidating turbulent convective heat transfer phenomena and the corresponding Nusselt number variation with cryogenic-propellant methane flowing under supercritical pressures with two different wall heat fluxes.Numerical results indicate that under supercritical pressures,the variations of thermophysical properties produce significant effects on turbulent heat transfer.Particularly in the critical region of methane,drastic property variations result in heat transfer deterioration.At a high wall heat flux,i.e.7 MW/m2,the heat transfer coefficient is improved with increasing pressure under supercritical conditions.The conventional heat transfer formula,although considering property variations,cannot be applied directly to calculate turbulent heat transfer coefficient of cryogenic-propellant methane under supercritical pressures.

Key words: Cryogenic methane;Supercritical pressure;Convection heat transfer;Numerical simulation