大宽隙比竖直矩形窄缝通道内混合对流传热的数值研究

Numerical Simulation on the Mixed Convection in a VerticalRectangular Narrow Channel

用k- ε双方程模型研究了大宽隙比( 通道宽度与通道间隙之比> 25) 矩形窄缝通道内单相流体的混合对流换热问题。数值模拟结果表明, 大宽隙比窄缝通道内的混合对流存在着与圆管内混合对流相似的“中部热岛”现象,在给定流量下,壁面“热岛”现象随热流密度增大而加强,给定热流时壁面“热岛”

This paper describes a numerical simulation of the mixed convection in a vertical rectangular narrow channel. The fluid's pressure is about 14 MPa, the heated flux is up to 0.8 MW/m2, and the ratio of channel's width to slot is larger than 25. The κ-ε turbulence model and the SIMPLE solution are employed in the simulation. The solution shows that there is a heat transfer deterioration region on the middle length of the wall.