Study on film cooling performance of fan-shaped hole with downstream cylindrical jet

摘要

This paper presents detailed computation and comparison in terms of film cooling adiabatic effectiveness, heat transfer coefficient, and Net Heat Flux Reduction (NHFR) for three film cooling hole geometries. The hole geometries investigated include a cylindrical hole and a fan-shaped hole with and without an assistant cylindrical jet. The computational domain geometry and flow conditions were chosen in a way to match data reported in the open literature. As compared to the cylindrical hole, fan-shaped hole with and without an assistant cylindrical jet provide improved protection of the surface over a wide range downstream film cooling hole and a better lateral spreading of the coolant, which leads to higher average film cooling performance, particularly at high blowing ratios. The presence of cylindrical hole downstream of fan-shaped hole somewhat increases adiabatic effectiveness and NHFR over a wide range of stream wise location. The blowing ratio has slightly effect on the film cooling performance for fan-shaped hole with and without assistant hole.