Pressure distribution effects due to chevron fences on film cooling effectiveness and flow structures

Abstract

In the present study, film cooling effectiveness behavior for novel fence geometries were investigated depending on flow structures and related pressure patterns. Eleven fence geometries are evaluated. Generally, it can be described as upstream chevrons with sharp and rounded edges instead of straight shapes. The film cooling effectiveness was investigated and compared with experiments with and without fences, which are available in literature review. Velocity profiles, static pressure coefficient profiles and turbulence kinetic energy contours were discussed. Blowing ratios in the range of 0.5, 1, 1.5 and 2 were investigated. Results show that the fence cases are characterized by three pressure coefficient peaks that are responsible for generating useful higher pressure difference between the leading edge of a film hole and the midline region to improve coolant lateral spreading. Results indicate that the best novel fence is chevron with rounded edge "case (e)" with higher film cooling effectiveness levels compared with the experiments. (C) 2016 Elsevier Ltd. All rights reserved.