摘要
为深入理解双燃烧室冲压发动机(DCR)增强燃烧机理,以超燃冲压发动机(SCR)为参照,基于CFD数值模拟技术对两类发动机进行了性能对比。燃料选用煤油C12H23,当量比0.8,采用六组分四步化学反应机理。结果表明,DCR能够增强燃烧并提高燃烧效率,且马赫数升高后,其提升效果不降反升。DCR增强燃烧机理在于两点:一是亚燃室的高温高压有效缩短了点火延迟进而促进了燃烧;二是其特殊的“三明治”火焰结构,反应区可同时向内外两个维度传播燃烧,反应面积大幅增大使得燃烧效率更高。DCR也能够提升发动机性能,但当马赫数升高后,由于DCR总压损失明显增大,其性能提升优势有所减弱。
In order to deeply understand the enhanced combustion mechanism of a dual-combustion ramjet(DCR),a scramjet engine(SCR)was used for comparison.The performance of the two engines was compared us⁃ing CFD numerical simulation.Kerosene C12H23 was used as fuel with an equivalent ratio of 0.8 and a chemical re⁃action mechanism of six components and four steps.The results showed that DCR can enhance combustion and improve combustion efficiency.The enhancement effect increases with the increase of Mach number.The DCR en⁃hanced combustion mechanism lies in two points:first,the high temperature and pressure of the subsonic com⁃bustor effectively shorten the ignition delay and promote combustion;second,its special“sandwich”flow field structure allows the reaction zone to simultaneously combust in both internal and external dimensions,greatly in⁃creasing the reaction area and making combustion efficiency higher.DCR can also improve engine performance,but as the Mach number increases,the total pressure loss of DCR increases significantly,weakening its perfor⁃mance improvement advantage.
作者
吴宪举
魏志军
王宁飞
林朝斌
韩万之
杨光
WU Xianju;WEI Zhijun;WANG Ningfei;LIN Chaobin;HAN Wanzhi;YANG Guang(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;School of Aeronautical Engineering,Taizhou University,Taizhou 318000,China)
出处
《推进技术》
EI
CAS
CSCD
北大核心
2024年第8期112-124,共13页
Journal of Propulsion Technology
基金
国家自然科学基金(U21B2086)。
关键词
DCR
增强燃烧
燃烧效率
点火延迟
“三明治”火焰结构
气流推力函数
Dual-combustion ramjet
Enhanced combustion
Combustion efficiency
Ignition delay
“Sandwich”flame structure
Stream thrust function
