变密度凸肋通道流动及换热特性研究

Channel Flow and Heat Transfer Characteristics with Variable Density Fin

文中通过数值模拟方法对变密度凸肋通道的流动和换热特性进行了研究,主要研究了恒定热流密度下肋片高度和截面形状对通道流动和换热性能的影响。物理模型包含4种肋片结构,高度为0.45~0.75 mm。结果表明,在Re=100~600时,水滴型肋片换热性能优于圆形肋片并随尾翼长度增加而增强。摩擦阻力系数随Re增加呈下降趋势,随肋片高度增加而增大但趋势逐渐减缓。综合性能随肋片高度增加具有先增大后减小趋势,并且随Re增大曲线趋于平缓。在肋片高度变化范围内,肋片高度为0.65 mm时,也即肋片顶部与通道之间存在一定间隙时,综合性能最优。

The flow and heat transfer characteristics of variable density fin channels were studied by numerical simulation.The effects of constant heat flux on the flow and heat transfer performance of the channel were studied.Four different fin shapes were used in the model,with the height of 0.45~0.75 mm.The results show that when Re=100~600,the heat transfer performance of the droplet fin is better than that of the round fin and increases with the length of the tail fin.The frictional resistance coefficient decreases with the increase of Re,increases with the increase of fin height,but the trend is slowing.The integrated performance increases with the increasing pin-fin height first,and then declines,the line tends to be gentle with the increasing of Re.In the range of fin height,the fin height is 0.65 mm,indicating that the performance is best when there is a certain gap between the pin-fin end face and the channel.