内燃机车车顶高温浮射流扩散规律的数值研究

Numerical study on the diffusion of high-temperature buoyant jet flow on internal combustion locomotive roof

内燃机车在高海拔偏远山区的非电气化铁路中得到了广泛应用,然而其在运行过程中,车顶产生的高温浮射流将紧贴车顶表面流动,导致列车车顶局部过热,从而影响列车的运行安全。基于实车试验验证的数值模拟方法,对高海拔地区运行的5辆编组列车(包括2节内燃机车)进行仿真研究,并分析了不同运行速度和射流入射角度对高温浮射流扩散特性的影响。研究结果表明:随着运行速度的提高,射流运动轨迹线降低,导致高温气流更贴近列车车顶,特别是当内燃机车以最高运行速度160 km/h运行时,列车车顶的高温区域达到最大;增大射流入射角度能够有效减轻高温浮射流受到的来流冲击作用,进而提高射流轨迹线并降低车顶表面温度,当高温浮射流的入射角度达到45°时,列车车顶最高温度下降51.6%。本研究的发现为降低高海拔铁路上内燃机车车顶设备损坏风险提供了重要的参考。

Internal combustion locomotives are widely used in non-electrified railways in remote,highaltitude mountainous areas.However,during their operation,a high-temperature buoyant jet emanating from the roof can lead to localized overheating of the roof surface,potentially undermining the train's operational safety.This paper conducted numerical simulations leveraging numerical methods validated through actual vehicle tests of five trains(including two internal combustion locomotives)operating in high-altitude regions to explore the diffusion characteristics of high-temperature buoyant jets under varying operational velocities and jet incidence angles.The results indicate that as the running speed increases,the high-temperature airflow moves closer to the train surface.Particularly,when the internal combustion locomotive operates at its peak speed of 160 km/h,the roof surface experiences the largest high-temperature region.Conversely,increasing the jet incidence angle can effectively mitigate the impact of the incoming flow on the high-temperature buoyant jet so that the jet trajectory is elevated farther away from the roof and the roof surface temperature decreases.Specifically,when the incidence angle of the high-temperature buoyant jet attains 45°,the maximum temperature of the roof decreases by a significant 51.6%.The findings of this study offer crucial insights for mitigating the risk of damage to internal combustion locomotive roof equipment on high-altitude railways.