过渡流下近壁插入双圆柱对壁面传热特性的影响（英文）

Effect of the Gap Ratio on Heat Transfer Characteristics in Transitional Flow at Two-tandem Cylinders near Wall

为了研究过渡流下间隙比对传热特性的影响,通过Fortran程序建立了近壁插入串列双圆柱的模拟模型.控制方程包括连续方程、不稳定Navier-stokes方程和能量方程,通过有限体积的方法进行求解.结果表明,Nusselt数有两个峰值.第一个峰值出现是由于下壁面和上游圆柱之间流体的加速.随着间隙比的增加,流体的加速效应减小,峰值的大小降低.第二个峰值是由于流体的加速和上游圆柱尾流的洗刷效应.随着间隙比的增加,存在一个最佳插入位置,使得洗刷效应和加速效应达到峰值.当Re=200,P_s=4D,近壁插入串列双圆柱存在一个最佳插入位置,使得壁面的传热特性最佳.

In order to investigate the effect of the gap ratio on heat transfer characteristics in transitional flow,a simulation model that two-tandem cylinders insert near the wall was established by using Fortran programmer.The governing equations including continuous equation,unsteady Navier-stokes equation and energy equation are solved by using the finite volume method.The results show that there are two peaks in the curves of Nusselt.The first peak is caused by the fluid acceleration between the down-wall and the upstream circular cylinder.With the increase of the gap ratio,the acceleration of the fluid decreases,and the value of the peak decreases.The second peak is caused by the fluid acceleration and the wake washing effect of the upstream circular cylinder.There exists the best position where the strength of the washing effect and the acceleration reach to the peak value with the increase of the gap ratio.It is concluded that in the case of Re=200 and P■=4D,there is an optimum insert position of two-tandem circular cylinders near wall,which can enhance the heat transfer.