I. Introduction erosene is used worldwide for aircrafts and rocket propulsion system. Many liquid rocket engines such as the F-1 engine, RD-170, RD-180 and on Merlin engine of Falcon 9 uses kerosene as propellant. Although cryogenic fueled rocket engines produce greater specific impulse than kerosene, the LOx/Kerosene engines are vastly used due to numerous other advantages. Density of kerosene is 10 times higher than LH2, which makes LOx/kerosene combination more competitive for booster stage engines due to lesser tank weight, even at the expense of performance. LOx/kerosene engine provides additional advantages of low operating cost ie producing kerosene is cheaper than producing LH2, ease of handling, and no insulation requirement for tanks compared to LH2. In order to get high thrust and combustion efficiency liquid rockets engines operate at high pressure. This high pressure requirement is fulfilled using turbo pumps which are turbine driven. Most liquid rockets use staged combustion power cycle in which propellants are partially consumed in preburner to produce hot gases, which powers the turbine. Preburner operates at high pressures and the propellants injected are exposed to supercritical conditions in the combustion chamber. At supercritical conditions, fluids have no clear inter-phase boundary and are no longer separated. In such conditions, rocket propellants exhibits gas like diffusivities and liquid like densities. The diminished inter-molecular forces and surface tension promote diffusion-dominated mixing prior to combustion.

The numerical modeling of such high pressure injection and supercritical combustion phenomenon poses a wide variety of thermodynamic and transport closure problems. Supercritical combustion for LH2/LO2 and LCH4/LO2 combination has been widely explored numerically and experimentally. Giorgi et al [1] simulated the high pressure injection, mixing and combustion of LOx/LCH4. Simulation with two equation k-ε model for turbulence and eddy dissipation model for chemistry closure was performed and phenomenon was validated with experimental observations. Investigation on effects of ideal gas and real gas modeling was carried out at operating pressure of 15 MPa. It was shown that ideal gas model gave erroneous thermo-fluidynamic fields in comparison to real gas density model. Poschner et al [2] simulated the LH2/LO2combustion at 6MPa using standard k-ε turbulence model and eddy dissipation combustion model. Peng Robinson equation of state was used and model was validated using OH mass fraction data from MASCOTTE RCM-3 test case [3]. Emre Sozer et al [4] simulated GO2/GH2 flame with laminar finite rate (LFR) combustion model and non-premixed assumed probability density function (PDF) with chemical equilibrium and chemical non-equilibrium formulations. SST k-ω model was employed for turbulence closure. The study showed that, LFR model predicted higher temperature near stoichiometric flame surface in comparison to non-premixed combustion model with chemical equilibrium formulation. It also highlighted insignificant change in results with chemical equilibrium and chemical non equilibrium formulations. Cutrone et al [5] simulated MASCOTTE V04 LOx/LCH4 test case and validated the model with experiments using mass fraction and temperature profiles. RANS based solver in combination with steady flamelet approach was employed. Recently, Yang et al [6] investigated LOx/LCH4 supercritical combustion phenomenon with LES turbulence model and steady flamelet approach. This paper reported the flame stabilisation, recirculation zones and mixing …