基于火焰面/进度变量方法模拟超临界压力下的液氧甲烷火焰  

Simulation of LO_(X)/CH4 flame under supercritical pressure based on flamelet/progress variable method

作　　者：李钰航 王祎 吴宝元 杨建文 LI Yuhang;WANG Yi;WU Baoyuan;YANG Jianwen(Key Laboratory for Liquid Rocket Engine Technology,Xi'an Aerospace Propulsion Institute,710100 Xi'an,China;Academy of Aerospace Propulsion Technology,710100 Xi'an,China)

机构地区：[1]西安航天动力研究所液体火箭发动机技术重点实验室,西安710100 [2]航天推进技术研究院,西安710100

出　　处：《应用力学学报》2022年第5期826-833,共8页Chinese Journal of Applied Mechanics

基　　金：民用航天技术预先研究资助项目(No.D020306)。

摘　　要：为了深入认识超临界压力下低温推进剂的复杂燃烧过程,基于OpenFOAM开源CFD仿真平台,采用真实流体热物性模型结合火焰面/进度变量模型建立了一套超临界湍流燃烧的均相模拟方法。针对Mascotte试验台的液氧甲烷燃烧实验进行了数值模拟,结果较准确地捕捉了火焰形态,同时研究了燃烧室压力对火焰的影响。研究表明:由于超临界压力下液氧在升温时存在拟沸腾过程,射流剪切层中液氧迅速膨胀并产生了径向向外的流动,造成了火焰的突然扩张并在火焰下游形成回流区;燃烧室压力升高时甲烷密度增加而入口速度减小,同时液氧升温膨胀的幅度减小,造成了火焰长度的增加以及火焰下游回流区的消失。In order to get an in-depth insight into the complicated combustion process of cryogenic propellant under supercritical pressure,a homogeneous simulation method of supercritical combustion is developed using open source CFD toolbox OpenFOAM,based on real-fluid thermo-physical model and flamelet/progress variable combustion model.The LO_(x)/CH_(4) flame of Mascotte combustor is simulated,and the effect of chamber pressure on flame structure is studied.Results show that due to the existence of pseudo-boiling process during LO_(x) heating up under supercritical pressure,the LO_(x) in shear layer expands rapidly along radial direction,leading to the reverse flow region downstream of the flame.During the rise of chamber pressure,the density of methane increases with its inlet velocity decrease,and the expanding extant of LO_(x) reduces,thus resulting in the increase of flame length and the vanishing of reverse flow region downstream of the flame.

关 键 词：超临界燃烧 低温推进剂 真实流体 火焰面进度变量模型 均相求解器 

分 类 号：V435[航空宇航科学与技术—航空宇航推进理论与工程]