不同倾角下管流中超临界CO₂对流换热特性的数值研究  

Numerical Study on Convective Heat Transfer Characteristics of Supercritical CO2 in Tube Flow at Different Inclinations

作　　者：寇升 胡勇 夏增虎 邱民京 张健鹏 

机构地区：[1]四川大学空天科学与工程学院,四川 成都

出　　处：《应用物理》2022年第4期213-225,共13页Applied Physics

摘　　要：针对高超声速飞行器面临的严苛工作环境,近年来利用超临界CO2作为冷却介质对飞行器进行传热保护成为一种很有发展前景的方法,本文结合高超声速飞行器飞行过程中有可能出现的不同迎角,采用了一种基于k-ω SST模型的湍流Prt模型(TWL模型),选择9个特殊角度(0˚ ≤ θ ≤ 180˚),定义流动方向和重力方向相同时倾斜角为0˚,对加热管内超临界CO2的流动传热进行了数值模拟。研究结果表明:相同工况下,流动方向对超临界CO2与壁面间的换热特性影响较大,当倾斜角大于90˚时将伴随传热恶化现象,且随着倾斜角的增大传热恶化现象愈发明显;当倾斜角小于等于90˚时将强化传热,但并非随着角度的减小传热现象持续改善,在30˚时获得最佳的传热表现而非0˚,所以重力是影响超临界CO2传热的重要因素,但并非唯一因素。In view of the harsh working environment faced by hypersonic aircraft, in recent years, the use of supercritical CO2 as a cooling medium for heat transfer protection of aircraft has become a promising method. This paper combines the different angles of attack that may occur during the flight of hypersonic aircraft, adopts a turbulence Prt model (TWL model) based on the k-ω SST model, selects 9 special angles (0˚ ≤ θ ≤ 180˚), defines the flow direction and gravity direction at the same time the tilt angle is 0˚. The flow heat transfer of supercritical CO2 in the heating tube is numerically simulated. The results show that under the same working conditions, the flow direction has a greater influence on the heat transfer characteristics between supercritical CO2 and the wall surface;when the inclination angle is greater than 90˚, it will be accompanied by heat transfer deterioration, and with the increase of the inclination angle, the heat transfer deterioration phenomenon will become more and more obvious;when the inclination angle is less than or equal to 90˚, the heat transfer phenomenon will be strengthened, but not with the reduction of the angle;the best heat transfer performance is obtained at 30˚, so gravity is an important factor affecting supercritical CO2 heat transfer, but it is not the only factor.

关 键 词：高超声速飞行器 超临界CO₂ 倾斜圆管 热防护 传热恶化 

分 类 号：TK1[动力工程及工程热物理—热能工程]