Unsteady Numerical Simulations of Transcritical Turbulent Combustion in Liquid Rocket Engines

摘要: In the past fifty years, most design parameters of combustion chamber Liquid Rocket Engines (LREs) have been adjusted without a detailed understanding phenomena, because both limited experimental diagnostics and numerical capabilities. The objective present thesis work is to conduct high-fidelity unsteady simulations transcritical reacting flows, in order improve flame dynamics LRE, eventually provide guidelines for their improvement. First real-gas thermodynamics its impact on schemes are presented. As Large-Eddy Simulation (LES) involves filtered equations, filtering effects induced by then highlighted typical 1D configuration specific artificial dissipation proposed smooth density gradients LES. Then, Direct Numerical (DNS) study turbulent mixing near-injector region LREs conducted. non-reacting case, vortex shedding wake lip injector shown play major role mixing, induces formation finger-like structures as observed experimentally similar operating conditions. attached rim local extinction disappear. structure analyzed various modes identified. Finally, LES H2/O2 jet flame, issuing from coaxial with inner recess, results first validated against data recess. recessed compared reference solution results, scrutinize this parameter efficiency.