关键词: 自激扫掠喷嘴, 高频动态扫掠喷射, 加力燃烧室, 振荡频率, 压力脉动, 流体振荡器

Abstract: In order to prove the feasibility of applying the self-excited sweeping nozzle in the afterburner, and the effectiveness of high frequency dynamic sweeping fuel injection methods for improving the efficiency of afterburner combustion, this study first designed a fuel spray bar integrated with the self-excited sweeping nozzles, and its basic working charac-teristics, such as flow rate, frequency and sweeping angle are tested, and further compared with the plain-orifice spray bar. Then, based on the rectangular afterburner test rig, under the same test conditions and the fuel-to-air ratio range, employing the plain-orifice spray bar and self-excited sweeping spray bar respectively, the overall combustion efficien-cies are tested and the dynamic wall pressure pulsation information is monitored. The results show that multiple self-sweeping nozzles can be integrated into the spray bar with the diameter limitation of 10mm. the flow capability of the self- excited sweeping spray bar is increased by 23%, compared to the plain-orifice spray bar with the equivalent ge-ometric flow area. For the nozzles in the same spray bar, their operating frequency and sweeping angle responses to the pressure drop are basically the same and have good consistency. The afterburner combustion efficiency is im-proved by 3.7%, by employing the self-excited sweeping spray bar，and no frequency which is same or close to the operating frequency of self- excited sweeping nozzle is found in the monitored wall pressure pulsation spectrum, indi-cating that high frequency dynamic sweeping fuel injection has no direct impact on the flame thermoacoustic oscilla-tion mode and large scale shedding vortex structure downstream the flameholder.

Key words: self-excited sweeping nozzle, high frequency dynamic sweeping fuel injection, afterburner, oscillation frequency, dynamic pressure pulsation, fluidic oscillator