再生式液体发射药火炮喷嘴内空化流动研究

Research of Cavitation Flow Inside the Nozzle of Regenerative Liquid Propellant Gun

为研究再生式液体发射药火炮喷嘴内部空化效应对射流雾化的影响,针对常用喷嘴结构建立了Euler多相流模型和空化模型,研究了喷嘴内部的空化流动现象,分析了喷嘴结构形式、内部倾斜角和喷射压力对喷嘴内部空化流动与喷嘴出口流动状态的影响规律。结果表明:RNG k-ε湍流模型比k-ε湍流模型更适于分析喷嘴内的空化流动现象;圆柱形和圆锥形喷嘴内部均发生空化流动现象;增大圆锥形喷嘴倾角导致空化增强,气液掺混区域变大,但流动速度受阻;大于10 MPa的喷射压力有利于形成稳定的空化流动。研究结果为优化喷嘴结构设计提供了理论依据,为进一步研究射流在燃烧室内的破碎、雾化、蒸发和燃烧过程提供了上游边界条件。

To study the influence of cavitation effect in the nozzle of regenerative liquid propellant gun(RLPG)on the jet atomization,the Euler multiphase-flow model and cavitation model were established for the common nozzle forms.The relative cavitation flow phenomenon in the nozzle was studied,and the effects of the nozzle structure,internal angle and injection pressure on cavitation and flow states at the exit were analyzed.Numerical results indicate that the RNG k-εturbulence model is more suitable for the simulation of cavitation than the k-εturbulence model.The cavitation phenomenon happens inside the cylindrical nozzle and the conical nozzle.With the increase of the internal angle of conical nozzle,the cavitation enhances,and the air-liquid mixing area becomes larger,but the flow velocity is impaired.It is beneficial to the formation of stable cavitation flow that the injection pressure is greater than 10 MPa.The study results provide the theoretical basis for the optimization of nozzle structure design,and promote the further research of the breakup,atomization,evaporation and combustion process of the jet in the combustion chamber.