同轴度对引射器性能影响的数值分析

Numerical simulation for the influence of alignment on injector performance

船用燃气轮机需要安装引射器来降低红外特征,受限于机舱尺寸,引射器的主喷管和混合管往往不能同轴线布置。为了研究主喷管和混合管在非同轴线布置下对引射器的影响,本文以某燃气轮机上带有冷却孔的引射器为研究对象,采用数值模拟的方法研究了主喷管相对混合管轴线偏离±30%,±50%,±70%时引射器的性能,并且对比了冷却孔在开闭状态下的性能。结果表明:当冷却孔关闭时,主喷管向负方向偏移时压力损失系数最大提高4.3%,向正方向偏移时压力损失系数最大提高2.5%;当冷却孔开启时,偏移方向对压力损失系数没有明显影响,且引射器内部的燃气总温降低100~150 K。

Injector is equipped on marine gas turbine for declining the infrared characteristic.The main nozzle and mixing pipe of injector usually can′t locate on the same axis for the limitation of engine room size.In order to research the influence of main nozzle and mixing pipe on injector under non-coaxial arrangement,this paper investigated the injector with cooling hole of a gas turbine,numerical simulation was adopted for researching the performance of injector when the axis of main nozzle was±30%,±50%and±70%away from the axis of mixing pipe,what′s more,the performances that cooling hole was open and closed were also compared.The results show that while cooling hole is closed,the pressure loss coefficient increases by 4.3%maximally when the main nozzle offset to negative direction,and increases by 2.5%maximally when main nozzle offset to positive direction;offset direction has little influence on pressure loss coefficient while cooling hole is open,and the total temperature of gas in the injector decreases by 100 to 150 K.