燃气发生器燃烧室实验研究

Experimental Study of a Gas Generator Combustor

燃气发生器可以有效解决低马赫数、低总温条件下液态煤油在超声速燃烧室中点火与稳定燃烧的困难。为给低马赫数条件下燃气发生器设计和强迫点火方式提供参考,在来流马赫数6、总温1650K条件下,开展了不同燃烧室结构、煤油的添加及分布、燃烧组织方式对点火和燃烧的影响实验研究。研究结果表明,随着出口喉道的减小,冷热工况燃烧室壁面压力增大,同时隔离段内受扰动最前点位置向上游移动。燃烧室出口面积与隔离段出口面积之比Q_S为0.50时,进气道在冷工况能够正常运行,热工况时煤油开始燃烧造成进气道喘振;Q_S为0.78和1.12时,进气道在冷热工况均可正常运行;Q_S为0.78,两个喷注位置组合下,煤油当量油气比达到11时能够成功点火并稳定燃烧,进气道正常启动,燃气发生器能够产生高温富油燃气。低驱动压、大喷孔的离心喷嘴喷注煤油更容易燃烧且燃烧效果更好。高富油条件下,以可添加煤油最大煤油量为分界,增加或减少煤油喷注量,可以作为小范围控制生成燃气温度的一种方式。

Gas generator can solve the difficulty of ignition and steady combustion of liquid kerosene in a supersonic combustor under the conditions of low Mach number and total temperature. In order to provide references to the design of gas generator and the ways of forced ignition in low Mach number free stream,wind tunnel experiments have been carried out to study the influences of the combustor construction, kerosene injection schemes and combustion organization under the free stream Mach 6 and total temperature 1650 K. The experimental results show that,with the decreasing of combustor throat,combustor wall pressure increase and the disturbance zone in isolator moves upstream for both cold and combustion cases. When QS=0.50（combustor exit area/isolate exit area）,inlet can start for cold case but buzz for combustion case. When QS=0.78 and 1.12,inlet can start for both cold and combustion cases. When QS=0.78 and kerosene/air ratio is 11 with two injection position,success in ignition and steady combustion are obtained,the inlet can start and gas generator can produce high temperature and rich fuel gas. Kerosene injected from swirl nozzle with low driving pressure and large injector can be ignited much easier and results in much better combustion efficiency. There exists a maximum of kerosene addition under the rich fuel gas condition which can be used to control the gas temperature by increase or decreasethe kerosene injection mass.