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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。
The properties of transport fluid and supercritical fluid under supercritical pressure were calculated by using the modified corresponding method, the basic thermodynamic relationship and the Soave-Redlich-Kwong (SRK) equation of state. These universal properties were compared with the computational fluid Based on CFD numerical model, aiming at the supercritical heat transfer and engine cooling phenomenon related to rocket propulsion system and hypersonic vehicle, a kind of typical hydrocarbon The effect of supercritical pressure on flow and heat transfer was analyzed in detail. The variation of Nusselt number of convective heat transfer was revealed. The numerical simulation results Compared with the existing empirical formula. The results show that under supercritical pressure, the Nusselt number decreases with the decrease of pressure, and turbulent heat transfer will deteriorate and fluctuate near the critical region.