肋片强化矩形截面螺旋通道换热特性研究

应用CFD软件研究肋片对矩形截面螺旋通道湍流换热的强化作用,基于正交螺旋坐标系分析通道内流场和温度场分布.结果表明:对于单一矩形截面螺旋通道,换热壁面中心线附近受二次流影响较弱,换热效果较差.在此处安装扰流肋片后,矩形截面中心处产生了附加的二次流.研究范围内,加装肋片后的对流换热系数α是未加装肋片的1.03~1.2倍,流动阻力系数f是未加装肋片的1.003~1.033倍;强化传热因子j在0.911~1.067之间.低雷诺数下的低高度肋片综合强化换热效果较好.

Heat Transfer Enhancement of Ribs in a Helical Duct with Rectangular Cross Section

CFD software was applied to study heat transfer enhancement effect of ribs in a helical duct with rectangular cross section. Fluid flow fields and temperature fields were displayed based on orthogonal helical coordinate system. Results showed that in a rectangular helical duct, the centre line of the heated wall was a relatively inferior position for heat transferring. This is for the reason of less secondary flow effect. By the way of attaching ribs on the center line of the heated wall, additional secondary flow vortices grew up. In the study range, the convective heat transfer coefficient with rib was 1.03 - 1.2 times that without rib and flow resistance coefficient is 1. 003 - 1.033 times. Heat transfer enhancement factor j was within 0. 911 - 1. 067. Better comprehensive effect of heat transfer enhancement would be achieved with lower Reynolds number and shorter ribs.