论文部分内容阅读
球窝、球凸结构具有较好的强化传热效果,在换热器、燃气轮机冷却通道等传热设备上有较大的应用前景。采用数值模拟方法研究带有二次球窝/凸结构的矩形换热通道的传热及阻力特性,计算中采用SST k–湍流模型求解粘性Navier-Stokes方程,分析二次球凸截面直径对于通道流动及传热的影响。研究结果表明:二次球凸的加入对球窝腔内部及其下游光滑尾迹区的流动有明显的控制作用,同时在很大程度上影响了换热区域的努塞尔数Nu分布。相比于单球窝通道,二次球凸加入后球窝腔内以及下游光滑尾迹区的换热得到了明显的强化,并且随着二次球凸截面直径的增大,传热强化的程度逐渐增大,同时通过压力损失系数的变化规律可知,布置二次球凸结构强化传热的同时带来的压力损失非常小,可见二次球凸是一种有效的小流阻强化传热手段。
Ball socket, ball convex structure has better heat transfer enhancement effect, in the heat exchanger, gas turbine cooling channels and other heat transfer equipment has a larger application prospect. Numerical simulation is used to study the heat transfer and resistance characteristics of rectangular heat exchange channels with double-ball / convex structure. SST k-turbulence model is used to solve the viscous Navier-Stokes equation. The diameter of secondary convex section is analyzed. Flow and heat transfer effects. The results show that the addition of quadratic bulbs has a significant effect on the flow in the interior of the ball cavity and its downstream wake region, and at the same time, it greatly affects the Nusselt Nu distribution in the heat transfer region. Compared with the single-ball channel, the heat transfer in the ball-socket cavity and the downstream smooth-wake area after the secondary ball-convex is added is obviously strengthened. With the increase of the diameter of the cross section of the secondary ball, the degree of heat transfer enhancement And the pressure loss coefficient change law shows that the arrangement of secondary spherical convex structure enhanced heat transfer at the same time bring the pressure loss is very small and can be seen that the secondary spherical convex is an effective means of strengthening the heat transfer of small flow resistance .