Study of loss mechanism in low speed compressor cascade using dissipation function

The transport equation of total pressure containing dissipation function was derived.Through experimental and numerical studies of a low speed compressor cascade,the characteristics of flow and loss distribution were discussed in detail,then the loss mechanism was obtained.The results show that:the high cascade loss originates from dissipation in the area near the blade leading edge,blade and end wall surface,wakes,as well as the area between the separation and mainstream.Moreover,the separation zone is only a low-energy fluid gathering area for large total pressure loss and entropy rather than a zone of loss source.The essences of improving the cascade performance by controlling separation are weakening the shear strength and reducing the strong shear zone in the area between the separation and mainstream by increasing the velocity and reducing separation area.A method of improving the cascade performance by controlling the evolution of boundary layer and horseshoe vortex at the cascade inlet is recommended.This paper presents a new thought of controlling cascade losses.