摘要
针对隔板喷嘴抑制高频不稳定燃烧问题,通过COMSOL数值仿真方法,从声能耗散角度研究了热粘性效应下不同隔板喷嘴间隙、直径、频率对声能耗散的影响规律。结果表明:热粘性在隔板喷嘴吸声中起到关键性作用;存在最佳隔板喷嘴间隙,使得隔板喷嘴的吸声效果最好;随着隔板喷嘴直径的增加,最佳声能耗散呈现递减趋势,最佳隔板喷嘴间隙呈现递增趋势;随着声波频率的增加,最佳声能耗散和最佳隔板喷嘴间隙均呈现递减趋势。研究结果为抑制火箭发动机不稳定燃烧的隔板喷嘴设计提供依据。
Baffled injectors play an important role in suppressing the high frequency instability emerged in liquid propellant rocket engines.However,the detailed mechanism of acoustic absorption enhanced by baffled injectors has not been explained clearly.To reveal the acoustic absorption mechanism of baffled injectors,a numerical model was developed in which a smooth change in pipe cross-sectional area was assumed and the thermal viscosity was taken into account.The results showed that the thermal viscosity dissipation of acoustic energy attributed to the enhanced acoustic absorption.A maximum acoustic absorption was observed and it showed a monotonic decrease with the increase of baffled injector diameter or frequency at the optimum gap.The optimum gap increased with the increase of diameter or decrease of frequency.This work may provide some guidance for the engineering design of baffled injectors.
作者
刘旺
李敬轩
杨立军
LIU Wang;LI Jingxuan;YANG Lijun(School of Astronautics,Beihang University,Beijing 100191,China)
出处
《载人航天》
CSCD
北大核心
2019年第4期468-474,共7页
Manned Spaceflight
关键词
隔板喷嘴
不稳定燃烧
数值仿真
声能耗散
baffled injectors
combustion instability
numerical simulation
acoustic absorption
