K.M. Pandy et al., International Journal of Advanced Trends in Computer Science and Engineering, 1 (1), March – April, 2012, 33-42 33 @ 2012 IJATCSE All Rights Reserved CFD Analysis of Supersonic combustion using Diamond shaped Strut Injector with standard K-Є Non-premixed Turbulence model K.M.Pandey, Professor, Department of Mechanical Engineering,N.I.T Silchar, India, kmpandey2001@yahoo.com Sukanta Roga, M.Tech Student, Department of Mechanical Engineering, N.I.T Silchar,India, sukanta.me42@gmail.com A.P.Singh, Lecturer,Department of Mechanical Engineering, N.I.T Silchar, India, hello2apsingh@gmail.com ABSTRACT In this paper the supersonic combustion of hydrogen using strut injector along with two-dimensional turbulent non- premixed combustion model. The present work is based on the standard k- ε which has been used for modeling the turbulence and single step finite rate chemistry. In this process, a PDF (Probability Density Function) approach is created and this method needs solution to a high dimensional PDF transport equation. After designing the model in GAMBIT, it is exported to FLEUNT software for analysis of combustion process with air inlet at Mach number 2 and hydrogen as the fuel with inlet Mach number 1. As the combustion of hydrogen fuel is injected from the strut injector, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature occurred in the recirculation areas which is produced due to shock wave- expansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is observed that there is very little amount of OH around 0.00233 were found out after combustion. By providing strut injector, expansion wave is created which cause the proper mixing between the fuels and air which results in complete combustion. Keywords: CFD, Combustion, Diamond-shaped Strut Injector Hydrogen Fuel, Non-premixed Combustion, Scramjet, Standard K-ε Turbulence Model, Steady State, Supersonic Combustion 1. INTRODUCTION Propulsion concepts such as the supersonic combustion ramjet (scramjet) and the shock-induced combustion ramjet (scramjet) utilize oxygen freely available in the atmosphere and thereby substantially reduce the weight penalty of on-board oxidizer tank used in rocket based systems. In the case of a hypersonic air-breather the challenge is increased due to the requirement of supersonic combustion. Flow velocities through the combustor on the order of thousands of meters per second provide the fuel and air with only a brief time to adequately combine. Contemporary mixing augmentation methods to address this issue have focused on fuel injection devices which promote axial vortices to enhance the mixing process. A scramjet engine is well known as hypersonic air-breathing engine in which heat release due to combustion process occurs in the supersonic flow relative to the engine. Therefore, the flow velocity throughout the scramjet remains supersonic and thereby it does not require mechanical chocking system [1]. Scramjet is an signifier for Supersonic Combustion Ramjet which is a type of jet engine aimed to operate in the high velocity regime usually it is related with rockets. Both are designed to be used for supersonic flight; however a Scramjet allows the flow through the engine to remain supersonic, whereas in a Ramjet the flow is slowed to subsonic levels before it enters the combustor which is the main difference between Scramjet and the Ramjet. Figure1 shows a basic generic Scramjet design. It works by injecting fuel into a flow of supersonic air. The air is at sufficiently high temperature and pressure for the fuel to combust and the resulting mixture is discharged from the engine at a higher pressure. The Scramjet engine is composed of four main sections: the inlet, isolator, combustor and exhaust [2]. Figure 1 : Generic Scramjet engine K.M.Pandey, T.Sivasakthivel and S.K. Reddy K.K [3][4] describe that there are many types of Fuel Injectors for Scramjet Engines. The fuel that is used by scramjets is usually either a liquid or a gas. The fuel and air need to be mixed about stoichiometric proportions for efficient combustion. The main problem of scramjet fuel injection is that the air flow is Volume 1, No.1, March – April 2012 International Journal of Advanced Trends in Computer Science and Engineering Available Online at www.warse.ijatcse.current