低雷诺数下涡轮叶栅流动分离实验与数值模拟

Experimental and numerical investigation on flow separation in turbine cascade with low Reynolds number

关键词:  低雷诺数  涡轮叶栅  流动分离  湍流模型

Key words:  Low Reynolds number  Turbine cascade  Flow separation  Turbulence model

摘要:

应用实验测量和数值模拟相结合的方法,研究了低雷诺数条件下高负荷涡轮叶栅吸力面的流动分离。通过对叶片表面压力系数、叶栅出口尾迹以及叶片表面气流分离位置和重新附着位置的比较发现,计算结果与实验结果吻合得相当好。应用本计算方法,对低雷诺数条件下雷诺数和来流湍流度对涡轮叶栅的流场的影响作了准确的模拟,对叶栅吸力面的气流分离、再附等做出了预测。实验研究和计算结果都表明,低雷诺数条件下叶栅损失的急剧增大是由于在低雷诺数条件下叶片吸力面发生了气流的分离,雷诺数越低或者进口湍流度越低,叶片吸力面的气流分离就越严重,由此导致的叶栅损失也就越大。

Abstract:

Experiments and numerical simulations were performed to study the flow separation occurred on the suction side of a highly-loaded turbine cascade at low Reynolds number.The detailed measurements on outflow field and loading distribution of turbine cascade were conducted.In all cases the calculated results exhibited fair agreement with experimental data in turbine cascade losses and loading distribution.The flow fields of turbine cascade were simulated,and the flow separation and transition were also predicted reasonably.Both he calculated and experimental results indicated that the main cause of increased notably losses with decreasing Reynolds number was the flow separation on the suction side of turbine blade.