EFFECTS OF MOMENTUM RATIO ON TURBULENT NONREACTING AND REACTING FLOWSIN A DUCTED ROCKET COMBUSTOR

A numerical study of turbulent nonreacting and reacting flows in a duc ted rocket combustor with an ASM turbulence model and a finite-rate co mbustion model is reported. In addition, detailed measurements of flow velocities and turbulence parameters have been conducted by use of a four-beam two-color LDV system. Three different values of the ratio of fuel momentum to air momentum were selected to investigate its effect s on the turbulent flow structure, mixing and combustion characteristi cs. It is found that the momentum ratio has strong effects on the numb er, size and rotational direction of dome region recirculation zones, reattachment length, axial fuel-jet spreading rate and penetration abi lity, flame temperature distributions and total pressure loss in the d ucted rocket combustor. A useful correlation between the reattachment length and momentum ratio is derived. Moreover, a moderate value of th e momentum ratio is recommended for better combustion performance and lower total pressure loss. The reported data are believed to provide v aluable guidelines for practical design of combustors.