发动机爆震室气液两相爆轰性质  

Gas-liquid two phase detonation properties in an engine detonation chamber

作　　者：王晨辰 翁培奋[1] 丁珏[1] 李家骅[1] 陈永杰[1] WANG Chenchen;WENG Peifen;DING Jue;LI Jiahua;CHEN Yongjie(Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《上海大学学报（自然科学版）》2018年第3期402-411,共10页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(11472167)

摘　　要：利用爆轰波产生周期性冲量是脉冲爆震发动机推进系统的关键.建立非定常两相爆轰的Eulerian-Lagrangian模型,以正庚烷液体燃料为例,采取高分辨率的MUSCL(monotonic upwind scheme for conservation law)格式,针对发动机爆震室气液两相爆轰的热力、动力学性质展开数值研究,计算所得的爆轰波压力与实验结果较为一致,且基于较小粒径的燃料液滴(25μm),计算爆轰波C-J(Chapman-Jouguet)状态对应的爆轰参数与理论值接近,验证了建立的模型和研究方法是正确的.同时,讨论爆轰管内燃料液滴粒径对爆轰波参数的影响.结果显示,在均匀预混时,液滴破碎蒸发域宽度仅与燃料初始粒径有关.随着燃料初始粒径的增大,液滴破碎蒸发域宽度增加,且两者存在线性关系.同时,当燃料初始粒径从25μm增大至100μm,爆轰波反应区宽度增大了240%,而爆轰的压力峰值从7.08 MPa降低至5.14 MPa.Periodic impulse generated by detonation waves is a key for a pulse detonation engine.To simulate inhomogeneous two-phase detonation,a new two-dimensional Eulerian-Lagrangian model that includes two-way coupling between gas and droplet phases is presented.Detonation of n-heptane in air/oxygen is simulated using the high resolution monotonic upwind scheme for conservation laws(MUSCLs)scheme to study thermodynamic and dynamic properties of two phase detonation.The computed detonation wave pressure is in agreement with experimental results.Based on the fuel droplets with a smaller particle size(25μm),the computed detonation parameters corresponding to the Chapman-Jouguet(C-J)state are close to the theoretical values.It verifies the model and the research method established in this paper.Moreover,effects of droplet sizes on the detonation process are discussed.The results show that droplet break and the evaporation domain is related to the droplet size for uniform premixing.As the initial particle size of the fuel increases,the liquid droplet breaks and the evaporation domain width increases,with linear relationship between them.When the initial particle size of the fuel is increased from 25μm to 100μm,the width of the reaction zone is increased by 240%,and the peak pressure of detonation is decreased from 7.08 MPa to 5.14 MPa.

关 键 词：两相爆轰 爆轰反应区 燃料液滴的粒径 欧拉–拉格朗日模型 

分 类 号：O359[理学—流体力学]