Faculty Publications
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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.Item Experimental and numerical investigation on the effect of turboprop engine exhaust gas impingement on pusher aircraft(Walter de Gruyter GmbH, 2023) Vinay, C.A.; Gottekere Narayanappa, K.; Yepuri, Y.G.Turboprop engines require an exhaust nozzle or stub to duct the engine exhaust flue gas outboard of the aircraft. The design of these exhaust stubs are dictated primarily by the aircraft's configuration. In pusher aircraft, the exhaust stubs are designed to minimize the exposure of the flue gases from the engine exhaust on the propeller blades and fuselage. A fluid-thermal-structure coupling analysis is performed to understand the thermal effects of the engine exhaust jet flow on the thermo-mechanical behavior of pusher configured light transport aircraft propeller and structure. The steady thermal flow field of the aircraft with forward and reverse thrust, in which propeller blade angle variations were analyzed for different aircraft speed. The present work investigates a three-dimensional analysis of flow around the nacelle-airframe and the effect of exhaust flue gas impingement on the propeller blade surface. Based on the insights from the numerical results, the designed exhaust duct was integrated on the aircraft and carried out ground static and flight testing for various flight operating conditions in which propeller blade and fuselage surface temperature were measured. Numerical and experimental results are compared and validated for certain flight conditions and found satisfactory. © 2023 De Gruyter. All rights reserved.