旋转状态下S型带肋通道流动特性数值研究

Numerical study of flow characteristics in rotating S-shaped passage with ribs

为了更好地了解涡轮叶片内冷完整通道中流体的流动特性,数值研究了肋、转弯以及旋转对完整S型带肋通道流动特性的影响.雷诺数为17 000,3个出口的出流比分别为27%,49%,24%,旋转数取0,0.03,0.06,0.09.结果表明:通道1靠近前缘侧阻塞比高,肋的扰流作用强,流体速度较低.转弯引起流体流动分离,使转弯下游通道中的主流发生偏移,通道3靠近分隔板侧存在较大范围低速区.旋转产生的切向哥氏力使流体向哥氏力指向面偏移,通道2与通道3主流分别偏向吸力面与压力面.旋转影响通道中二次流的分布,增强转弯下游低速回流涡区域流体的流动.

For better understanding of the flow characteristics of turbine blade internal cooling passage,a numerical study was conducted to investigate the influences of rib,turn and rotation on the flow characteristics in full S-shaped passage with ribs.The Reynolds number was 17 000,three outlet discharge ratios were 27%,49%,24%,rotation numbers were 0,0.03,0.06,0.09.The results reveal that the fluid has stronger turbulence and lower velocity with higher blockage ratio near the leading edge of passage 1.Turn causes the flow separation and shift of mainstream downstream the turn.There is a big range of low velocity area near the bulkhead in the passage 3.Coriolis force makes the fluid shift towards the wall to which the Coriolis force points,the mainstream shifts towards suction surface and pressure surface in passage 2and passage 3respectively.Rotation affects the distribution of the secondary flow in passage and promotes the flow of low velocity circumfluence area downstream the turn.