氨气射流卷吸特性的数值仿真  

Numerical Simulation for Entrainment Characteristics of Gaseous Ammonia Jet

作　　者：沈浩昱 雷艳[1] 尹燕旭 赵天瑀 衣玥 仇滔[1] Shen Haoyu;Lei Yan;Yin Yanxu;Zhao Tianyu;Yi Yue;Qiu Tao(College of Mechanical and Energy Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学机械与能源工程学院,北京100124

出　　处：《内燃机学报》2024年第5期412-420,共9页Transactions of CSICE

基　　金：国家自然科学基金资助项目(52371302).

摘　　要：基于Ansys Fluent软件进行三维数值仿真,研究了氨气射流贯穿距特性及卷吸特性,分析了射流形成的亚膨胀区结构及涡流特点,并利用控制截面法对氨气射流的卷吸质量特性进行了研究.结果表明:氨气射流贯穿距的发展分为三阶段,这种三段式特点由氨气射流形成的一次涡及剪切层的特性所引起;第一阶段(0<t<0.14 ms)为线性阶段,在亚膨胀区及其边界氨气射流对空气无卷吸;第二阶段(0.14 ms≤t≤0.40 ms)为过渡阶段,在该阶段内一次涡及剪切层快速发展,卷吸质量增加了50%以上(喷压比R为8.0);第三阶段(t>0.40 ms)为准稳态阶段,卷吸质量较最大值减少30%(喷压比为8.0).平均卷吸空气总质量随喷压比增加而增大,第一、二阶段一次涡存在时平均瞬时卷吸空气质量较大,剪切层充分发展时平均瞬时卷吸空气质量达到最大值,卷吸质量最多增长58%(喷压比为8.0).Based on the software of Ansys Fluent,a three dimensional numerical simulation of ammonia gas jet was carried out to study the characteristics of jet penetration and ambient air entrainment.Both the under-expended area of the ammonia gas jet and the vortex structure were analyzed.The results show that the development of ammonia jet penetration presents a three-staged pattern,which has a strong correlation with jet formed initial vortex and shear layer.The first stage(0<t<0.14 ms)is the linear stage where ambient air is hardly entrained at jet boundary and under-expanded area.The second stage(0.14 ms≤t≤0.40 ms)is the transient stage where initial vortex and shear layer have a rapid development while the mass of entrained air increases over 50%(R=8.0).The third stage(t>0.40 ms)is the quasi-steady stage where the maximum mass of entrained air decreases by 30%(R=8.0).Average mass of entrained air increases with the increase of the nozzle pressure ratio R.The average transient mass of entrained air increases when the initial vortex exists at the first and second stage,peaks at which the shear layer fully develops,where mass of entrained air increases to 58%(R=8.0).

关 键 词：氨气 气体燃料射流 卷吸 数值仿真 流动 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]