高阻塞比肋化通道对流换热特性实验研究

为了降低涡轮叶片温度以保证其安全性,采用实验方法对高阻塞比肋化通道内流动换热特性进行了测量。针对顺排和叉排两种肋化通道考察了多个主要影响因素对换热特性的影响规律,研究表明:(1)对于高阻塞比肋化通道,当流体在层流区域流动时,肋片对流体在通道内部对流换热的强化作用要明显高于湍流状态;(2)无论是顺排还是叉排肋化通道,当肋间距比为10时,其对应着最大的对流换热系数和最大的流阻损失;(3)在实验几何参数范围内,顺排肋化通道的对流换热系数和流阻系数均高于叉排通道;(4)在高阻塞比肋化通道中,流阻特性的变化规律和流动状态的转变规律基本与水力光滑通道相同。

Experimental Study on Heat Transfer Characteristics of High Blockage Ribs Channel

In order to reduce the turbine blade temperature to ensure the safety, the experimental method is used to investigate the flow and heat transfer characteristic of ribbed channel with high blockage ratio, and the influence of several main factors on heat transfer characteristics is investigated for two kinds of ribbed channel with symmetric and staggered ribs. The experimental results show that:(1) The heat transfer coefficients are increased with the increase of Reynolds number, though at the cost of higher pressure losses; (2) when the rib spacing to height ratio is 10, it keeps the highest heat transfer coefficient in three kinds of rib spacing to height ratio 5, 10 and 15; (3) the heat transfer coefficient of symmetric arrangement ribs is higher than that of the staggered arrangement ribs, but the pressure losses of symmetric arrangement ribs is larger than that of the staggered arrangement ribs; (4) compared with one-side ribbed channel, the heat transfer coefficient of two-side ribbed channel is distinctly higher.