推导了含耗散函数项的总压输运方程,利用总压损失、熵增、耗散函数等参数分析某扩压叶栅流动与损失特性,探讨其损失产生机理.研究表明:栅内损失主要来源于叶片前缘附近、流道表面、尾迹区、分离区与主流交界区的流动耗散;分离区仅是高总压损失和高熵值的低能流体聚集区,而非高损失来源区;通过减小分离区以提高叶栅性能的控制方法本质是通过增加分离区的速度或减小分离区来减弱其与主流的剪切强度或减小强剪切作用区;控制叶片前缘附近附面层和马蹄涡的发展也是提高叶栅气动性能的途径之一.上述研究为叶栅流动损失控制研究提供了一种思路.
The transport equation of total pressure containing dissipation functi on was derived.Through experimental and numerical studies of a low speed compres sor cascade,the characteristics of flow and loss distribution were discussed in detail,then the loss mechanism was obtained.The results show that:the high casca de loss originates from dissipation in the area near the blade leading edge,blad e and end wall surface,wakes,as well as the area between the separation and main stream.Moreover,the separation zone is only a low-energy fluid gathering area fo r large total pressure loss and entropy rather than a zone of loss source.The es sences of improving the cascade performance by controlling separation are weaken ing the shear strength and reducing the strong shear zone in the area between th e separation and mainstream by increasing the velocity and reducing separation a rea.A method of improving the cascade performance by controlling the evolution o f boundary layer and horseshoe vortex at the cascade inlet is recommended.This p aper presents a new thought of controlling cascade losses.