关键词: 多点喷射, 涡系结构, 波瓣喷嘴, 燃烧特性, 数值模拟

Abstract: In order to investigate the influence of the lobe-induced vortices on the combustion characteristics of the multi-point injection combustor, a lobe combustion chamber model was established comparing to reference test of swirling multi-point injection combustor to verify model validity of the subsequent combustion process simulations. Combustor model of flow simulation test bench was tested to confirm the model availability of flow characteristic based on the similarity principle. The test bench consisted of a lobe combustion chamber model, a controller, a flow meter and a high-speed camera under the same working conditions as that of multi-point injection swirling combustor test, namely idle, 30% power, cruise and take-off conditions. Flow field vortex structure, multi-quantity field of combustion and combustion characteristics were studied by mathematics and physical simulations. For each working condition, a comparative study of calculation and experimental verification was carried out to verify the creditability of the combustion flow characteristics. The results showed the flow vortex structure in the combustion chamber verified the simulation results. The overall flow field had the similar structures for each working condition. Along the flow direction, the induced vortices structure at the exit of the lobe which mainly formed from streamwise vortex and the orthogonal vortex was similar, the vortices structure variation changed regularly. With the decrease of oil/gas ratio, the streamwise vortex and orthogonal vortex dimensions increased gradually, the NOx emission gradually decreased, the combustion efficiency gradually increased and outlet temperature field quality improved. The lobe nozzle combustion chamber showed the excellent performance and effective control in the multi-point injection lobe combustor by varied operating conditions. The multi-physical fields such as fluid flow and combustion temperature improved more effectively than that of reference. Lobe combustion chamber model had the rationality and application value to its engineering application.

Key words: Multipoint Injection, Vortex structure, Lobe nozzle, Combustion characteristics, Numerical Simulation