带扰流圆柱肋楔形通道的流动与换热数值研究

Numerical Study on Heat Transfer and Pressure Loss in Wedge-shaped Ducts with Cylindrical Pin-fins

建立了带扰流圆柱肋楔形通道内的换热与压力损失数值计算模型,采用ANSYS-CFX商用软件数值研究了楔形通道内叉排和顺排柱肋的换热与压损特性,分析了流动与结构参数的影响规律。结果表明:随雷诺数的增大,柱肋表面、柱肋排以及通道底面的平均努赛尔数呈增大趋势;随着x/D的增大,柱肋表面和柱肋排的平均努赛尔数有所降低;随着楔形通道收缩角的增大,柱肋表面和通道底面的平均努赛尔数略有增强;相同条件下的叉排柱肋换热效果要好于顺排柱肋换热效果。范宁摩擦系数随雷诺数增加而略有增大,随x/D增大有较大的降低,随着收缩角的增大而增大。在计算参数内,叉排柱肋且x/D为1.5时的热力性能系数最高。

In this article,a numerical computational model of heat transfer and pressure loss in wedge-shaped ducts with cylindrical pin-fins was established,and by using the ANSYS-CFX software,the heat transfer and pressure loss in both wedge-shaped ducts with in-line and staggered array pin-fins were researched numerically. The effects of flow and structure parameters were analyzed. The results show that,as the Reynolds number increases,the averaged Nu numbers of pin-fin surface,pin-fin row and bottom surface of the ducts also increase. The averaged Nu numbers of pin-fin surface and pin-fin row decrease with the increase of x/D（ ratio of streamwise pin-pitch to pin-fin diameter）. Also as the contraction angle of the ducts becomes larger,the mean Nu numbers of pin-fin surface and bottom surface of the ducts slightly increase. While in the same conditions,staggered array pin-fins have a better performance in heat transfer than in-line array pin-fins. Fanning friction factor slightly increases as the Reynolds number increases,greatly decreases with the increase of x/D value and increases with the increase of the contraction angle. Under all the circumstances concerned in this article,the staggered array pin-fins whose x/D value is 1. 5 have the highest thermodynamic performance factor.