【摘要】 采用整体求解法对常物性的冷、热流体在三通道同心套管中层流逆流流动时的导热与对流耦合传热问题,进行了数值模拟.结果表明,3个通道除各自的入口段局部努塞尔数Nu沿通道变化外,其后均为充分发展段,局部Nu保持不变,且通道内侧的换热比外侧好.固体与流体的导热系数之比λsf对耦合换热产生影响,耦合情况下的Nu比均匀热流边界条件下的Nu要小,随λsf的减小,固壁内的导热对Nu的影响加大.更多还原

【Abstract】 The coupled conduction and convection heat transfer in the concentric cannula in which the gas with constant properties is countercurrent and in laminar flow is studied and simulated.An integrative solution is used here to solve the coupled problem.The results show that the local Nu is constant and doesn′t vary along the tube length except at the entrance. And the heat exchange on the inner side is better than that on the outer side. The ratio of conduction coefficient between the solid and the fluid, namely λsf, has some effect on the conjugated heat transfer. The coupled Nu is smaller than that with uniform heat flow boundary. The conduction of the solid wall has more effect on the Nu with the decrease of λ_sf.更多还原