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本文考虑在透平进口存在热斑时,对受动静干涉和叶顶间隙影响的热斑非定常迁移特性以及近壁面区域的热负荷变化规律进行研究。结果表明:热斑在动叶通道中的形态发生较大变化,并存在冷热流体分离现象;在通道涡、泄漏流以及密度梯度产生的次流涡等涡系的联合作用下,压力面侧的热斑流体逐渐向上下端壁延伸,而吸力面侧逐渐向中叶展聚集;随着顶部间隙高度的增大,泄漏涡与通道涡的干涉作用增强,流道中心流体受泄漏涡的挤压而向压力面侧偏移,引起压力面附近温度梯度的增大,同时由于泄漏量的增加,使叶顶附近壁面两侧的传热环境均趋于恶化。
In this paper, when the hot spot is present in the turbine inlet, the unsteady heat transfer characteristics of the hot spots and the heat load changes near the wall are studied. The results show that the morphology of the hot spot changes greatly in the moving blade passage, and there is separation of hot and cold fluid. Under the combined action of channel vortex, leakage flow and secondary vortex vortex with density gradient, The hot spot fluid gradually extended to the upper and lower end walls, while the suction side gradually gathered to the middle leaf. With the increase of the top clearance, the interference between the leakage vortex and the passage vortex increased. The fluid in the center of the flow passage was squeezed by the leakage vortex Offset to the pressure side, causing the temperature gradient near the pressure surface to increase. At the same time, due to the increase of leakage, the heat transfer environment on both sides of the wall near the tip tends to be deteriorated.