COMPUTATIONAL ANALYSIS OF SUPERSONIC COMBUSTION USING CAVITY BASED FUEL INJECTION WITH SPECIES TRANSPORT MODEL AT MACH NUMBER 4.17 Prateek Srivastava and K.M. Pandey 1 M. Tech Scholar, Department of Mechanical Engineering, NIT Silchar, Assam, India 2 Professor, Department of Mechanical Engineering, NIT Silchar, Assam, India E-mail: 1 prateeksrivastava028@gmail.com, 2 kmpandey2001@yahoo.com Abstract: This paper describes the numerical investigation of Supersonic combustion with Hydrogen as fuel injected with cavity of L/D ratio of 3 in two dimensional combustor at Mach number 4 using species transport model for combustion. In the present study the flow regime is simulated by using reailizable k- (two equations) model with standard wall function. The hydrogen fuel is injected just upstream of the cavity. A cavity flame holder is provided which injects hydrogen fuel in a supersonic hot air stream that facilitates enhanced mixing and combustion efficiency. The cavity is of interest because recirculation flow in cavity would provide a stable flame holding while enhancing the rate of mixing or combustion. The combustor with cavity is found to enhance mixing and combustion while increasing the pressure loss, compared with the case without cavity. But it is noted that there exists an appropriate length of cavity regarding the combustion efficiency and total pressure loss. Index Terms: Flameholder, k- model, Scramjet and Supersonic combustion. 1. Introduction Supersonic combustion ramjet (SCRAMJET) engines which poses some major challenges that has attracted the attention and imagination of researchers worldwide. Ramjet also referred as “Flying Stovepipe” is an air breathing jet engine in which supersonic combustion take place & does not have rotating parts. The air enters the inlet & diffuser which is used for the compression of air Compression depends on velocity and increases strongly with vehicle speed. The same air enters to a combustion chamber which is mixed with injected fuel. This mixture is ignited and burns in the presence and aid of a flame holder that stabilizes the flame. In order to provide sustained combustion cavity flame holder is provided along the flow of combusting material, it was first proposed by the CIAM (Central Institution of Aviation Motors) in Moscow, was used for the first time in a joint Russian/French dual-mode scramjet flight-test. Due to the cavity the recirculation of the flow International Journal of Science, Environment ISSN 2278-3687 (O) and Technology, Vol. 3, No 3, 2014, 923 – 930 1 2 Received Apr 16, 2014 * Published June 2, 2014 * www.ijset.net