摘要
为了研究连续爆轰发动机中的起爆、湮灭、再起爆和稳定全过程的流场演化机制,采用基于开源计算流体力学平台OpenFOAM的自定义求解器BYRFoam,使用带Laval尾喷管的空心圆筒燃烧室的几何构型及阵列式小孔进气。分析了起爆和湮灭的过程以及再起爆现象产生的原因,采用时空分布图的分析方法总结了起爆、湮灭、再起爆和稳定全过程的流场演化机制。结果表明,起爆初期的斜激波会在尾喷管收缩段反射形成反射激波,反射激波进入新鲜气体,形成与初始爆轰波方向相反的新爆轰波,这会导致爆轰波的湮灭。湮灭之后,燃烧室头部的高压强会阻碍新鲜气体的进入,之后已燃气体逐渐通过尾喷管排出燃烧室,燃烧室头部压强降低,逐渐进入燃烧室的新鲜气体为后续的再起爆创造了条件。连续爆轰波再起爆的原因有两个:一是尾喷管收缩段处的反射激波进入新鲜气体层并转化为爆轰波;二是已经形成的爆轰波与阵列式进气相互作用,形成反传波,反传波进入新鲜气体并转化为爆轰波。再起爆之后,经过爆轰波、激波和新鲜气体的相互作用和演化,爆轰波最终稳定传播。
To study the flow field evolution mechanism for the whole process of ignition,quenching,reinitiation,and stabilization in a continuous detonation engine,the in-house solver BYRFoam based on the open-source computational fluid dynamics platform OpenFOAM is adopted.The array of injection holes and the geometry of the hollow combustor with a Laval nozzle are used.The process of ignition and quenching and the cause of reinitiation are analyzed.The flow field evolution mechanism for the whole process of ignition,quenching,reinitiation,and stabilization is summarized by the spatio-temporal distribution method.The results show that the oblique shock wave at the initial stage of ignition will be reflected in the contraction section of the tail nozzle to form a reflected shock wave,which enters the fresh gas and forms a new detonation wave opposite to the initial detonation wave,causing the detonation wave to quench.Following quenching,the high pressure at the head of the combustor will hinder the entry of fresh gas,then the gas is gradually discharged from the combustor through the tail nozzle,and the pressure at the head of the combustor is reduced.The gradual introduction of fresh gas into the combustor creates the conditions for reinitiation.There are two possible reasons for the resumption of continuous detonation waves.One is that the reflected shock wave at the contraction section of the tail nozzle enters the fresh gas layer and evolves into a detonation wave.The other is that the formed detonation wave interacts with the array of injection holes to form reversed shock waves,which enters the fresh gas and evolves into detonation waves.Detonation waves finally propagate stably after the reinitiation due to the interaction and evolution of detonation waves,shock waves,and fresh gas.
作者
荣光耀
程杪
盛兆华
张允祯
刘向阳
王健平
RONG Guang-yao;CHENG Miao;SHENG Zhao-hua;ZHANG Yun-zhen;LIU Xiang-yang;WANG Jian-ping(Center for Combustion and Propulsion&CAPT&SKLTCS&Department of Mechanics and Engineering Sciences&College of Engineering,Peking University,Beijing 100871,China)
出处
《火炸药学报》
EI
CAS
CSCD
北大核心
2022年第6期785-792,共8页
Chinese Journal of Explosives & Propellants
基金
国家自然科学基金(No.91741202,No.52076003)。
关键词
爆炸力学
连续爆轰发动机
湮灭再起爆
反射激波
反传波
尾喷管
explosion mechanics
continuous detonation engine
quenching and reinitiation
reflected shock wave
reversed shock wave
tail nozzle
