航空煤油超临界压力流/固/热耦合数值模拟

Numerical Study of Conjugate Heat Transfer of Aviation Kerosene at Supercritical Pressures

本文针对中国3号航空煤油在超燃冲压发动机冷却通道内的超临界压力流动和传热现象,开展了流/固/热耦合的三维数值模拟研究.在准确考虑热物性变化的基础上,探讨了壁面热流密度及流体的入口速度对超临界压力传热过程的影响。结果表明,由于航空煤油在低流速下的传热效果较差,会造成冷却通道壁面温度在加热入口段快速升高;固体热传导现象在航空煤油超临界压力传热中变得非常重要,冷却通道侧壁面和下壁面固体温升现象突出;不同对流换热经验公式在航空煤油超临界压力传热中的适用性和应用范围也得到了初步的验证。

Numerical studies are conducted for three-dimensional conjugate heat transfer of aviation kerosene in engine cooling channels at supercritical pressures,with accurate calculations of thermophysical properties.The research is closely related to the regenerative cooling of supersonic combustion ramjet engines.Effects of the wall heat flux and inlet flow velocity on the heat transfer processes are carefully examined.Results indicate that fluid temperature increases sharply near the thermal entry region,because of the weak heat transfer performance of kerosene at a low inlet flow velocity.As a result,the surface temperature at the side and bottom channel walls increases significantly due to strong thermal conduction in the solid region.The applicability and accuracy of empirical heat transfer expressions in convective heat transfer of kerosene at supercritical pressures are verified.