超临界压力下航空煤油水平管内对流换热特性数值研究

Numerical study of convective heat transfer characteristics of kerosene flowing in a horizontal pipe at supercritical pressure

采用RNG(renormalization group)k-ε湍流模型和近壁区的Wolfstein一方程模型对超临界压力下大庆RP-3航空煤油在水平圆管内的流动和换热特性进行了数值研究.超临界压力下,由于航空煤油在拟临界点附近热物性的剧烈变化,浮升力将引起显著的二次流动.二次流动使得水平圆管的下表面湍流强度和对流换热增强,而上表面的湍流强度和对流换热减弱.最后分析了两种水平管内对流换热受浮升力影响判别标准在超临界流体中的适用性.

RNG（renormalization group） k-ε turbulent model combined with Wolfstein one-equation model in the vicinity of the wall was used to calculate the convective heat transfer properties of Daqing RP-3 aviation kerosene in a horizontal pipe at a supercritical pressure.A significant secondary flow was generated by the buoyancy effect due to the dramatic changes of the thermophysical properties of the kerosene near the pseudo-critical point.The secondary flow enhanced the turbulence intensity and convective heat transfer on the bottom of the pipe,and reduced the turbulence intensity and heat transfer on the top.Finally,the applicability of two criteria,used for the buoyancy effect on the convective heat transfer of horizontal pipes,was analyzed and compared at the supercritical conditions.