Copyright ⓒ The Korean Society for Aeronautical & Space Sciences Received: December 14, 2015 Revised: September 15, 2016 Accepted: September 19, 2016 341 http://ijass.org pISSN: 2093-274x eISSN: 2093-2480 Paper Int’l J. of Aeronautical & Space Sci. 17(3), 341–351 (2016) DOI: http://dx.doi.org/10.5139/IJASS.2016.17.3.341 Effect Of Hole Shapes, Orientation And Hole Arrangements On Film Cooling Effectiveness Prakhar Jindal*, A.K. Roy** and R.P. Sharma*** Department of Mechanical Engineering, Birla Institute of Technology, Mesra, Ranchi, JH 835215, India. Abstract In this present work, the effect of hole shapes, orientation and hole arrangements on film cooling effectiveness has been carried out. For this work a flat plate has been considered for the computational model. Computational analysis of film cooling effectiveness using different hole shapes with no streamwise inclination has been carried out. Initially, the model with an inclination of 30° has been veriied with the experimental data. he validation results are well in agreement with the results taken from literature. Five diferent hole shapes viz. Cylindrical, Elliptic, Triangular, Semi-Cylindrical and Semi-Elliptic have been compared and validated over a wide range of blowing ratios. he blowing ratios ranged from 0.67 to 1.67. Later, orientation of holes have also been varied along with the number of rows and hole arrangements in rows. he performance of ilm cooling scheme has been given in terms of centerline and laterally averaged adiabatic efectiveness. Semi-elliptic hole utilizes half of the mass low as in other hole shapes and gives nominal values of efectiveness. he triangular hole geometry shows higher values of efectiveness than other hole geometries. But when compared on the basis of efectiveness and coolant mass consumption, Semi-elliptic hole came out to give best results. Key words: CFD, Film cooling, hole shapes, blowing ratio, efectiveness, Orientation. Nomenclature T ∞ Free stream temperature, K T aw Adiabatic wall temperature, K T c Coolant temperature, K η Adiabatic cooling efectiveness,  ∞ −    ∞ −   M Mass lux ratio or blowing ratio (deined as ratio of mass lux of coolant to the mainstream) θ Non-dimensional Temperature,   −     −   1. Introduction he thermal management and protection of the components and surfaces in rocket engine combustion chambers presents one of the most challenging problems for designers. Film cooling is an active cooling strategy, which involves the continuous injection of a thin layer of protective luid (coolant) near a wall or boundary to insulate it from rapidly lowing hot propellant gases. Its main advantages are that it allows for the use of much lighter-weight nozzle assemblies and it is relatively simple to implement from a fabrication standpoint. Film cooling is usually measured in dimensionless form known as “ilm cooling efectiveness” , and deined as: η =  ∞ −    ∞ −   (1) where, T w is adiabatic wall temperature, T ∞ is freestream temperature = 600 K, & T c is coolant inlet temperature =300 K To study ilm cooling phenomena, investigators have been using simple geometries to reduce the complexity of the low afecting the heat exchange between the test surface and the mainstream gas low. he geometrically simple form of This is an Open Access article distributed under the terms of the Creative Com- mons Attribution Non-Commercial License (http://creativecommons.org/licenses/by- nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduc- tion in any medium, provided the original work is properly cited. * Ph. D Student, Corresponding author: prakharj@bitmesra.ac.in ** Associate Professor *** Professor (341~351)15-180.indd 341 2016-10-04 오후 3:21:10