【作者】 张新桥；

【导师】 李清廉；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2011， 硕士

【摘要】 本文通过理论分析、试验和数值仿真研究了空气/煤油/水燃气发生器的点火特性与燃烧性能。研究结果对空气/煤油/水燃气发生器的设计、性能改进和试验方案的制定具有重要意义。首先,通过冷态喷雾试验研究了燃气发生器喷嘴的流量特性和雾化特性,并对燃气发生器喷注器两种布局结构进行了喷雾试验,优选雾化性能较好的喷注器布局方式。试验结果表明:涡流器离心式喷嘴较其他喷嘴具有更优的雾化性能,因此选用涡流器离心式喷嘴进行热试;单圈6喷嘴均布的喷注器布局方式比单圈3喷嘴的布局方式具有更好的雾化粒子均匀性,雾化粒度也更细。其次,搭建了燃气发生器热试试验台,通过试验研究该型燃气发生器点火特性和燃烧性能。通过改变燃气发生器余氧系数、调节空气环缝宽度、加装火焰稳定器及更换火焰稳定器位置等方式、调节时序等方式,实现该型燃气发生器的可靠点火。研究了余氧系数、火焰稳定器、含水量等因素对燃气发生器燃烧稳定性和燃烧效率的影响规律。研究结果表明:对于该型燃气发生器,实现点火必须借助合适的火焰稳定器;余氧系数过低和过高都不能实现成功点火,余氧系数过低总温低,无法点着火,同等流量下余氧系数过高会导致气流过大,火焰无法稳定;恰当的时序对于点火成功与否至关重要。最后,对安装V型槽火焰稳定器的燃发器稳态流场、V型槽安装位置、V型槽阻塞比、双V型槽火焰稳定器方案等进行了数值仿真。仿真结果表明:V型槽火焰稳定器存在合适的安装范围;高阻塞比的火焰稳定器可以提高点火成功率;水的加入可以在一定程度上提高煤油的蒸发速率,但是存在一个最优值;双V型槽火焰稳定器需要对阻塞比搭配、V型槽安装距离和稳定器安装位置进行优化设计。更多还原

【Abstract】 Theoretical analysis, experimental investigation and numerical simulation of the ignition characteristic and combustion performance of air/kerosene/water gas generator are conducted in this essay. The results are of great significance to the design, performance improvement and experiment setup of air/kerosene/water gas generator.Firstly, cold spray experiments are used to study the flow characteristics and atomization property of gas generator injector, and spray experiments of two distribution structures of gas generator injectors are conducted to choose one distribution manner of better atomization property. The results suggest that: swirl injector used vortex generator has better atomization property than other injectors, so it is used in hot tests; compared with the distribution manner of single circle with three injectors, the distribution manner of single circle with six injectors equally distributed has better atomization particle equality and thinner atomization particle.Secondly, gas generator hot test test-bed has been set up to investigate the ignition characteristic and combustion performance of this gas generator by experiments. The reliable ignition of this gas generator is achieved by changing gas generator excess oxidizer coefficient, adjusting air slot width, installing flame stabilization facility and varying its position, regulating time sequence, etc. Excess oxidizer coefficient, flame stabilization facility, water content, etc. have been studied in the influence of flame stability and combustion efficiency in gas generator. The results show that: it is necessary to rely on appropriate flame stabilization facility in this gas generator to realize ignition; excessive high or low oxidizer coefficient is unable to realize ignition, for excessive low oxidizer coefficient contributes to low total temperature and excessive high oxidizer coefficient in same flux results in high flow and flame instability; appropriate time sequence is quite important to ignition.Finally, numerical simulation method has studied the flow field of gas generator with Vee gutter flameholder, Vee gutter installation position, Vee gutter choke ratio and double Vee gutter flameholder design. Results indicate that: the installation of Vee gutter flameholder has a proper range; high choke ratio improves the success rate of ignition; water injection can increase kerosene evaporation rate with a certain extent, however, there exists an optimum amount; choke ratio matching, Vee gutter installation distance and flameholder installation position need to be optimum designed in double Vee gutter flameholder.更多还原