关键词: 超临界压力, 正庚烷, 变物性, 对流传热, 数值模拟

Abstract: This article establishes a general numerical scheme which incorporates the accurate transport and thermodynamic property calculations of a fluid under supercritical pressures based on a modified corresponding-state method and the fundamental thermodynamic relationships with the Soave-Redlich-Kwong (SRK) equation of state. A comprehensive numerical investigation of the turbulent convective heat transfer with n-heptane, a typical hydrocarbon fuel, under supercritical pressures is systematically conducted. This heat transfer phenomenon is closely related to engine cooling technique in rocket and hypersonic propulsion systems. The effect of the supercritical pressure on fluid flows and heat transfer phenomena is examined in detail. Variations of the Nusselt number are elucidated and compared with those obtained from the available empirical formulae. Numerical results indicate that under supercritical pressures, the Nusselt number decreases with decreasing pressure, and that turbulent heat transfer becomes weakened and slightly oscillated near the critical region.

Key words: supercritical pressure, n-heptane, property variation, convective heat transfer, numerical simulation