Film cooling effectiveness and flow structures for novel upstream steps

Abstract

In this study, computational simulations were made using ANSYS CFX to predict the improvements in film cooling performance by using novel upstream steps. There are twenty-one novel steps consisting of three groups are tested. The first group consists of a rectangular step with different tilt angles. The second group consists of a normal rectangular step with and without segmentation. The third group consists of curved steps with and without segmentation. Optimizing the curved steps dimensions is performed. The film cooling effectiveness (1) of twenty-one novel steps were investigated and compared with experiment. Velocity profiles, pressure coefficient profiles and turbulent kinetic energy contours were discussed. Blowing ratios in the range (0.5, 1, 1.5 and 2) were investigated. Results indicate that the best novel step is the curved step with width (W/8) and the average values of film cooling effectiveness is increased to 138.8% compared with the experiment. (C) 2015 Elsevier Ltd. All rights reserved.