针对雷诺数为 40000 下涡轮叶片内部三通道旋流冷却结构进行瞬态热色液晶实验与数值模拟研究,并与普通转折通道进行比较分析.通过瞬态实验获得壁面高精度的努塞尔数分布与通道的沿程压力损失,结合数值计算结果得到如下结论:旋流通道显著增强了系统的换热能力与换热均匀性,第2、第3流程的壁面平均努塞尔数比普通转折通道分别提升了60%、57%;转折位置的冲击损失与节流损失是三通道结构的主要压力损失;旋流通道的全通道压力系数约为普通转折通道的3倍,且随着雷诺数的增大有增大的趋势;数值计算显示旋流通道内总压损失比静压损失减少了25%,使用总压分析沿程压力系数更为合理.
A transient thermal liquid crystal experiment and the numerical simulation were conducted on the three-channel swirling cooling structure inside the turbine blade. The results were compared with those of the ordinary turning channel at when Reynolds number is 40000. By conducting the transient experiment, high precision distribution of Nusselt numbers and the pressure loss along the channel were obtained. Combined with the numerical calculation results, the following conclusions were drawn: the swirl channel significantly enhanced the heat transfer capacity and the heat transfer uniformity of the system. Compared with the ordinary turning channel, the average Nusselt numbers on the wall of the second and third processes were increased by 60% and 57%, respectively. The impact loss and the throttling loss at the turning position were the main pressure losses of the three-channel structure. The pressure coefficient of the whole system of the swirl channel was about three times that of the ordinary turning channel, and it increased with Reynolds number. Numerical calculation indicated that the total pressure loss in the swirl channel was reduced by 25% compared with the static pressure loss. It was more scientific and reasonable to use the total pressure to analyze the pressure coefficient along the channel.
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