逆主流射流式旋涡发生器对涡轮流动分离控制数值模拟

Numerical simulation of the reversed injection VGJs for low-pressure turbine separation control

关键词:  低雷诺数  逆主流VGJs+  湍流发生器+  数值仿真

Key words:  Low Reynolds number  Reversed injection VGJs+  Turbulence generator+  Numerical simulations

摘要:

通过数值计算,详细研究了射流偏转角与主流夹角大于90°的逆主流小孔稳态射流(Reversed in jectionVG Js)对低雷诺数涡轮流动分离的控制。研究结果发现,逆主流射流对主流的扰动引起射流孔后边界层迅速转捩可抑制流动分离现象。射流作为"湍流发生器"从控制机理上有别于90°偏转角VG Js射流状态。高射流湍流度(10%),135°逆主流VG Js在达到与90°偏转角VG Js基本相同的流动分离控制效果时,可降低射流流量67%。

Abstract:

Detailed numerical simulations were performed to study the mechanics of the using Reversed injection VGJs(Vortex Generator Jets)to control the flow separation occurred on the suction side of low pressure turbine at low Reynolds numbers.The results show that the fully developed turbulence boundary layers on the blade surface caused by reversed injection VGJs restrain the flow separation.This mechanism of separation control is very different from the 90° VGJs.The reversed injection VGJs can be treated as the Turbulence Intensity Generator.The VGJs with 135° skew angle could reduce the injection mass 67% compared to the 90° VGJs at the nearly same flow separation control performance.It showed that the VGJs with 135° skew angle may be a better way to reduce the flow loss.