超临界压力下正庚烷的湍流传热数值研究

 应用修正的对应态方法、基本的热力学关系式和Soave-Redlich-Kwong(SRK)状态方程计算了超临界压力下流体的传输物性和热力学性质，并将这些普适性的物性计算方法与计算流体力学（CFD）数值模型相结合，针对火箭推进系统、高超声速飞行器相关的超临界传热和发动机冷却现象，在准确考虑热力学性质和传输物性变化情况下，系统地研究了一种典型的碳氢燃料——正庚烷在超临界压力下的湍流传热现象，详细分析了超临界压力对流动和传热的影响，揭示了对流换热努塞尔数的变化规律，并将数值模拟计算结果与已有经验公式进行了比较。计算结果显示在超临界压力下，努塞尔数随着压力的降低而降低，并且在临界区域附近会出现湍流传热的恶化和波动现象。

Numerical Study on Turbulent Convective Heat Transfer with n-heptane Under Supercritical Pressures

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.