带错排V肋和反V肋矩形通道强化传热机理及规律研究

采用热色液晶瞬态测量技术研究了带45°V肋和45°反V肋的矩形通道端壁的传热特性,分析V肋诱导产生二次流强化传热机理及其传热系数分布规律。通道进口雷诺数变化范围是10 460~32 100,肋高与当量直径的比为0.13,肋间距与肋高的比为10。实验结果表明:带V肋和反V肋矩形通道传热系数随着雷诺数的增大而增大;正V肋诱导产生沿V肋从中间向两侧发展的二次流,反V肋片诱导气流沿肋方向产生从两边流向中间的二次流;斜置V肋诱导产生的二次流增强了通道的传热能力;带V肋通道的传热强于带反V肋通道。

Study of the Mechanism and Variation Law Governing the Intensified Heat Transfer in a Rectangular Channel with Staggered V-shaped Ribs and Inverted V-shaped Ribs

The thermochromic liquid crystal transient measurement technology was used to study the heat transfer characteristics of the endwall of a rectangular channel with V-shaped ribs inclined at an angle of 45 degrees and inverted V-shaped ribs inclined at an angle of 45 degrees and analyze the mechanism governing the intensified heat transfer of the secondary flow induced by the V-shaped ribs and the law governing the distribution of the heat transfer coeffecient.The Reynolds number at the inlet of the channel ranged from 10 460 to 32 100,the ratio of the rib height and equivalent diameter was 0.13 and the ratio of the rib interval and height was 10.The test results show that the heat transfer coefficient of the channel with V-shaped ribs and inverted V-shaped ribs will increase with an increase of the Reynolds number.The positive V-shaped ribs will induce and produce a secondary flow which will flow from the middle to both sides along the V-shaped rib direction while the inverted V-shaped ribs will induce and produce a secondary flow which will flow from both sides to the middle.The obliquely arranged ribs will induce and produce a secondary flow which will enhance the ability of the channel to transfer heat.The ability of the channel with V-shaped ribs is superior to that of the channel with inverted V-shaped ribs.