论文部分内容阅读
在静止条件下,通过数值模拟的方法对接近真实的带前缘涡轮工作叶片腔模型内的流动与换热进行了分析.结果表明:腔内斜肋引发的三维涡对换热产生了巨大的影响,在一倍肋高范围内,Y-Z和X-Y平面上都出现了肋后涡,使得此处传热系数降低;在X-Z平面上,第2通道产生一对方向相反的涡,第3通道只产生一个涡.两个通道中的涡都占据整个横截面,这些涡增加了通道流阻.冲击和气膜流动主导了前缘通道内的换热,冲击产生的一对涡加强了流动掺混,促进了前缘吸、压力面上的换热,而高速的气膜出流推动了这一过程.相同流量工况下,第2通道带肋表面的平均换热和局部换热都是最好的,而光滑的第1通道总压降最小,综合换热性能在各个通道中最高.随着雷诺数的增加,各通道吸、压力面的局部换热和平均换热都增强,但压降系数变化不大.
Under quiescent conditions, the flow and heat transfer near to the true working vane cavity model with leading edge turbine were analyzed by numerical simulation. The results show that the three-dimensional vortex heat transfer induced by diagonal rib in the cavity has a huge In the range of one rib height, rib back vortices appear on the YZ and XY planes, resulting in a decrease of the heat transfer coefficient here. In the XZ plane, the second channel produces a pair of opposite vortices, and the third channel only Resulting in a vortex.The vortices in both channels occupy the whole cross-section, and these vortices increase the channel flow resistance.The impact and film flow dominate the heat exchange in the frontal channel, and a pair of vortexes generated by the impact enhance the flow mixing, Which promoted the heat transfer on the suction and pressure surfaces of the leading edge and the high velocity gas film outlet promoted this process.At the same flow rate, the average heat transfer and local heat transfer of the ribbed surface of the second channel were the best , While the smooth first channel has the lowest total pressure drop and the overall heat exchange performance is the highest among all channels.With the increase of Reynolds number, the local heat transfer and average heat transfer of suction and pressure surfaces of each channel are enhanced, but the pressure drop The coefficient changes little.