Numerical Investigation of Gaseous Hydrogen and Liquid Oxygen Combustion under Subcritical Condition

Abstract

This study is on combustion modeling of gaseous hydrogen and cryogenic liquid oxygen at the subcritical condition for the well-known Mascotte laboratory combustor. The proposed strategy relies on the hybrid Eulerian−Lagrangian framework in which the continuous phase is evaluated by Reynolds Average Navier−Stokes (RANS) equations and the quick discretization method. The dispersed phase of the combustion field is evaluated by the Discrete Phase Method (DPM). The Eddy Dissipation Concept (EDC) has been performed for combustion−turbulence interaction modeling. Effects of the turbulence model, chemical kinetic mechanism, equation of state, and inlet momentum jet flux are investigated in terms of combustion field characteristics. The accuracy of predictions is identified through a detailed comparison with the experimental databases gathered on the ONERA Mascotte test bench. Results show that predictions using the κ−ε turbulence model family, consisting of standard and renormalization group (RNG) models, are closer to the measurements. In order to investigate the effect of compressibility on combustion flow field, compressible and incompressible forms of the ideal gas equation of state have been utilized. Mach number and compressibility factor values in the vicinity of the injector post emphasize application of the compressible form of ideal gas. Four reduced chemical kinetic mechanisms are performed to compute chemical properties. It is found that the result of all mechanisms are highly similar; however the Burke mechanism can be selected as the best. Moreover, the C10 test case has been modeled to study the effect of mixture ratio change. Well-stirred reactor (WSR) modeling shows no differences in H 2 oxidation, neither routes nor reaction rates; and all differences in results refer to less H 2 /O 2 momentum flux and unburnt fuel for C10.

Experimental Study on the Unsteady Spray Combustion Process of a Liquid Oxygen/Methane Swirl Coaxial Injector

“…Recently, liquid oxygen (LOx)/methane has been regarded as the better propellant combination for high-thrust liquid rocket engines. , The LOx/methane liquid rocket engine is a potential propulsion for a reusable launch vehicle and heavy lift launch vehicle booster due to its desirable properties, such as high specific impulse, low cost, environmentally friendly performance, and reusability . As the critical component of liquid rocket engines, injectors greatly affect the atomization, evaporation, mixing, and combustion process of the propellant. − Compared with gas–liquid coaxial shear injectors, gas–liquid swirl coaxial (GLSC) injectors have better atomization performance, higher combustion efficiency, and improved combustion stability …”