摘要
低标高有限空间喷流的发展过程及掺混过程,是揭示热喷流流动特性的迫切问题。采用大涡模拟计算研究地面热喷流气动特性,建立不同离地高度的超声速喷管模型,对总温为870 K、马赫数为1.526的热喷流状态开展数值模拟,分析有限空间喷流的发展过程。首先评估了喷流模型温度分布和速度分布,随后在此基础上,对比了2种模型涡核发展过程,并通过试验予以了验证。研究表明:有限空间与自由空间喷流场涡核发展过程大致相同。有限空间喷流在核心区长度10D_(j)(D_(j)为喷管出口直径)位置时,地面开始对喷流产生影响,导致地面温度升高;在核心区长度10D_(j)位置以后,由于地面对喷流的影响,使得喷流与空气的掺混加剧,喷流在地面的作用下诱导出二次涡流,涡核分布更加集中,且其中以大尺度发卡涡为主。研究结果为相关工作提供了参考。
The development process and blending characteristics of the hot jet in a confined space is an urgent problem to reveal the temperature flow characteristics.The aerodynamic characteristics of the hot jet in presence of the ground were studied,employing the unsteady large eddy simulation.The supersonic nozzle models with different altitudes were investigated.The hot jet flow with a total temperature of 870 K and a mach number of 1.526 was numerically simulated.The development process of the jet flow in a confined space was analyzed.First,the temperature distribution and velocity distribution of the jet flow were evaluated.On this basis,the development process of vortex structure of the two models was compared and verified by experiments.The results show that the development process of the vortex structure in the confined space is similar with that in the free space.When X/D_(j)=10(D_(j)is the diameter of nozzle outlet),the ground begins to affect the jet flow,leading to the increase of the ground temperature.After X/D_(j)>10,due to the influence of the ground on the jet flow,the mixing of the jet flow and the air is more intensified.The secondary vortex structure is induced by the jet flow under the action of the ground,and the distribution of the vortex structure is more concentrated,in which the large-scale hairpin vortex is dominant.The results will provide a reference for relevant research.
作者
陈鹏飞
史亚林
杨华
王衡
刘志友
CHEN Pengfei;SHI Yalin;YANG Hua;WANG Heng;LIU Zhiyou(AECC Sichuan Gas Turbine Establishment,Mianyang 621000,China;School of Power and Energy,Northwestern Polytechnical University,Xi’an 71002,China)
出处
《燃气涡轮试验与研究》
2023年第3期1-7,共7页
Gas Turbine Experiment and Research
关键词
航空发动机
热喷流
大涡模拟
涡环
雷诺应力
aero-engine
hot jet
large eddy simulation
vortex structure
Reynolds stress
