Faculty Publications
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Item Experimental study of adiabatic cooling effectiveness on an effusion cooled test plate with machined ring geometries(Begell House Inc. orders@begellhouse.com, 2018) Jesuraj, J.; Rajendran, R.; Kumar, G.N.; Yepuri, Y.G.The present study deals with experimental investigation of adiabatic cooling effectiveness on an effusion cooled test plate with machined ring geometries. Initial tests were performed on an effusion cooling holes. The cooling effectiveness at the beginning of effusion holes is lower, and it increases in the flow direction mainly due to the additive effect of film cooling effectiveness of the effusion cooling geometry. Subsequent tests were done with machined ring geometries fixed ahead of effusion cooling hole geometry to improve the cooling effectiveness before the beginning of effusion cooling holes. These machined ring geometries act as a wall jet and reduce the hot side heat load by film cooling performance. Tests were performed at a coolant to mainstream density ratio of 1.3 and at blowing ratios ranging from 0.5 to 2.5. Increase in the blowing ratio shows an increase in the cooling effectiveness. Comparison results show that the adiabatic cooling effectiveness increases significantly before the effusion cooling holes in the presence of machined ring geometries at all blowing ratios. © 2018 by Begell House, Inc.Item Experimental and Numerical Investigation of Effusion Cooling Performance Over Combustor Liner Flat Plate Model(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2019) Jesuraj, J.; Rajendran, R.; Kumar, G.N.; Yepuri, Y.G.; Karthik, M.K.; Ramesha, D.K.This article presents a study of cooling performance of combustor liner of a gas turbine, using a flat plate model. The combustion process in gas turbine engines liberates very high temperature gases, which impacts the properties of the combustor liner. Hence, cooling of liner is important and is carried out by effusion cooling method. Experiments are carried out over a flat plate with staggered effusion holes. The hot mainstream air flows at a Reynolds number of 2.325 × 105, which indicates a turbulent flow. The coolant to mainstream density ratios of 1.3 and 1.5 is maintained by varying the blowing ratios ranging from 0.5 to 2.5. Test plate surface temperature measurements are recorded by an infrared camera and the overall cooling effectiveness in the flow direction is calculated. Numerical validation for conjugate heat transfer analysis is performed using ANSYS workbench and the temperature contours obtained are compared with infrared camera images. MATLAB program is used to obtain the effectiveness contours for experimental and computational fluid dynamics results. The effectiveness contours are found to be similar, showing the increase in effectiveness with the increase in blowing ratios. Density ratios comparison shows that with the increase in density ratio, the overall cooling effectiveness marginally decreases. © 2018, © 2018 Taylor & Francis Group, LLC.