液氧甲烷燃气发生器燃烧不稳定性预测仿真  

Numerical simulation to predict the combustion instability of liquid oxygen/methane gas generator

作　　者：鞠睿立 乔文通 张冰冰 成锦博 李敬轩 富庆飞[1,2] JU Ruili;QIAO Wentong;ZHANG Bingbing;CHENG Jinbo;LI Jingxuan;FU Qingfei(School of Astronautics,Beihang University,Beijing 100191,China;Ningbo Institute of Technology,Beihang University,Ningbo 315100,China)

机构地区：[1]北京航空航天大学宇航学院,北京100191 [2]北京航空航天大学宁波创新研究院,浙江宁波315100

出　　处：《火箭推进》2025年第1期156-167,共12页Journal of Rocket Propulsion

基　　金：国家自然科学基金(12272026,11922201,U1837211)。

摘　　要：燃烧不稳定现象严重危害着火箭发动机的正常工作,预测并消除燃烧不稳定对提高系统可靠性意义重大。为了研究某型号液体火箭发动机燃气发生器的高频纵向燃烧不稳定问题,基于热声解耦法对两种给定工况在2阶纵向-0阶切向-0阶径向模态下的燃烧不稳定性进行预测。采用通用CFD软件Fluent对稳态燃烧场及不同来流扰动频率下的非稳态燃烧场进行数值仿真计算,提取热释放率并计算火焰传递函数。结合声学仿真求解热源扰动下燃烧室的Helmholtz方程,得到模态频率及声学模态增长率,进而判断出对应声学模态下燃烧室的热声不稳定性。结果表明:在2阶纵向-0阶切向-0阶径向模态下,工况1能够稳定燃烧,而工况2出现燃烧不稳定现象。热声解耦法对于预测液氧甲烷发动机燃烧不稳定性可提供一定的参考。The phenomenon of unstable combustion seriously endangers the normal operation of rocket engines,predicting and eliminating unstable combustion is of great significance for improving system reliability.In order to study the high-frequency longitudinal combustion instability of a certain liquid rocket engine gas generator,the combustion instability of two given conditions under the second-order longitudinal,zero-order tangential and zero-order radial mode was predicted based on the thermos-acoustic decoupling method.The general CFD software Fluent was used to simulate the steady-state combustion field and the combustion field under different incoming flow disturbance frequencies,extract the heat release rate and calculate the flame transfer function.Combined with acoustic simulation,the Helmholtz equation of combustion chamber under heat source disturbance was solved,the modal frequency and acoustic modal growth rate were obtained,and then the thermal acoustic instability of the combustion chamber under corresponding acoustic mode was determined.The results show that the condition 1 is stable under the 2-order longitudinal and 0-order tangential and 0-order radial mode,while condition 2 exhibits combustion instability.The thermoacoustic decoupling method can provide a reference for predicting the combustion instability of liquid oxygen methane engines.

关 键 词：液体火箭发动机 燃烧不稳定 数值模拟 热声解耦 声学模态 

分 类 号：V434.22[航空宇航科学与技术—航空宇航推进理论与工程]