基于定容燃烧弹氨高压喷射闪沸喷雾特性研究

The research on flash boiling spray of ammonia fuel can provide a theoretical basis for the optimization of spray and combustion effect of internal combustion engine.Based on this purpose,the spray test of liquid ammonia was carried out with high temperature and high pressure constant volume combustion bomb.At the same time,spray modeling calibration research and model simulation were carried out.The simulation focuses on exploring the influence degree of injection pressure and environmental pressure on flash boiling spray.It is found that with the increase of injection pressure,the development of flash boiling spray is accelerated and the droplet breakage is enhanced because fuel obtains greater kinetic energy.In addition,the flash boiling spray showed an iron anchor shape with development.Environmental back pressure has a great influence on flash boiling spray.With the increase of environmental back pressure,the penetration distance of flash boiling spray is reduced due to the reduction of the pressure difference inside and outside the spray hole and the obstruction of environmental gas.In addition,the late spray development of the intense flash boiling spray and the transition flash boiling spray is different.The degree of vaporization of the fuel droplets in the intense flash boiling state is higher,while the degree of vaporization of the droplets in the transition state is lower.