支板/凹腔组合稳焰器耦合机制研究

Aiming at the problem of efficient and stable combustion of a typical Rocket Based Combined Cycle（RBCC）engine，three-dimensional numerical simulation of strut/cavity combined flame stabilizer in the model combustion chamber was carried out. Based on local flow characteristics，regularities of heat release，eddy structure and mass transport characteristics，the flame stabilization performance and coupling mechanism of the strut/cavity flame stabilizer under the flight Mach number 6.0 were analyzed. The study shows that flame stabilization performance of the cavity is affected by the mass transport characteristics between cavity and main flow. However，with the addition of strut，the spiraling eddy structure at the trailing edge of the strut makes the fuel transfer from the recirculation zone of strut to that of cavity. Then the residence time of fuel in the recirculation zone increases，mixing efficiency is enhanced and local heat release increases in cavity. Under the action of different eddy structure，the mass exchange rate between cavity and main flow accounts for about 10% to 20% of the incoming air flow. Better structure of eddy and characteristics of mass transport will increase combustion temperature by 9% in flame stabilization zone and increase combustion efficiency by more than 10%.Therefore，the flame stabilization performance of the strut/cavity combined flame stabilizer is affected by local eddy structure and gas mass transport characteristics. When the distance between the strut and cavity is shortened，the coupling effect between them is stronger and the performance of combustion and flame stabilization is better.