钝体形状对无限宽平板内流换热的影响

Effects of Vortex Generator Type on Heat Transfer Enhancement in Infinite Size Channel Flow

利用计算流体力学(CFD)方法研究二维无限宽平板层流流动时钝体形状对平板强化换热的影响。建立并求解描述流场对流换热的二维Navier-Stokes方程组及能量方程,时间项采用二阶隐式离散格式。计算圆柱形、方柱形、三角形和折角形这4种典型结构对平板对流换热强化性能的影响规律。结果表明:采用三角形钝体结构时,平板的平均努塞尔数最大,流道内阻力系数也最大;流体绕过钝体后产生的大尺度涡脱落以及平板表面产生的二次涡是影响钝体强化平板对流换热的重要因素。

The inclined vortex generator type effects on the heat transfer enhancement in channel flow is numerically investigated in this paper. The 2D unsteady Navier - Stokes and energy equations are solved,where the two-order implicit scheme is taken to be the temporal scheme,and the structures of square cylinders,circular cylinders,triangular cylinders,and triangular angle types are investigated. The results showthat both the average Nusselt number and the friction coefficient reach maximum when the triangular cylinder is used. It is also concluded that the large scale vortex shed from the cylinder and secondary vortexesgenerated on the channel walls are key factors that enhance the heat transfer on walls.