流速及进出液口形式对板式热沉换热性能影响

Effects of velocities and inlet-outlet forms on heat transfer of plate-style heat sink

热沉的换热性能直接影响空间冷环境的模拟效果。文章通过建立不锈钢板式热沉的几何结构模型,利用流体力学理论和有限元方法对板式热沉换热性能进行数值模拟。湍流计算采用RNG模型的k-ε方程,压力–速度耦合计算采用Simple算法,得到热沉壁面温度分布及换热特性参数,同时分析流速及进出口形式对热沉壁面温度均匀性及换热性能的影响。结果表明:较小的流速会导致热沉壁面温度均匀性变差,而流速的增加可以提高热沉的换热效率,但又会增加流体的压力损失。为保证热沉壁面温度分布均匀,需在综合考虑传热和阻力问题的基础上来确定最优的入口流速。当热沉有效尺寸较小时,则进出口布置形式不会影响板式热沉壁面温度的均匀性。

The heat transfer performance of a heat sink directly affects the simulation results for the space cold environment. This paper establishes a heat sink geometry model, to simulate the heat transfer performance of the heat sink based on the hydrodynamic theory and the finite element method. In the pressure-velocity coupling computation, the Simple algorithm is used and the RNG turbulence model is employed to calculate the heat sink temperature distribution and the heat transfer parameters. The influencing factors of the heat sink temperature uniformity and the heat transfer characteristics are analyzed. The results show that the heat sink temperature uniformity is poor when the flow rate is small. Only above a certain flow rate can the heat sink temperature distribution uniformity be ensured. The increase of the flow rate can improve the heat transfer efficiency of the heat sink, but it also increases the fluid pressure loss. The heat transfer and resistance should be taken into account to determine the optimal inlet flow rate. The forms of the inlet and the outlet do not affect the heat sink wall temperature uniformity when the effective size of the heat sink is small.