The high-temperature buoyant jet emitted from the roof of an internal combustion locomotive influences the outflow field distribution and the heat dissipation performance of downstream equipment.Investigating the influence of the high temperature buoyant jet on the aerodynamic characteristics surrounding the vehicle body is beneficial for evaluating the heat dissipation environment of downstream equipment.The realizable k-ε two-equation turbulence model,grounded in the three-dimensional,unsteady,and compressible Reynolds-averaged Navier-Stokes approach,was employed to simulate the 5-car high-speed train.The results are benchmarked against the test results.In addition,the diffusion effects of high-temperature jets at varying altitudes and train speeds were examined.Results are shown as follows.As the altitude increases,atmospheric density diminishes,the inertia force of the high-temperature gas emitted by the diesel engine intensifies,leading to an enhanced upward trend in airflow and a reduction in the maximum surface temperature of the train.As the operating environment's altitude increases from 3000 m to 5000 m,the maximum temperature on the diesel locomotive's roof decreases from 117 ℃ to 86 ℃.As the train's speed increases,the high-temperature air emitted by the diesel engine approaches the train's surface more closely,leading to a higher maximum temperature on the roof.At a speed of 80 km/h and an altitude of 3000 m,the train roof's maximum temperature reaches 81 ℃,whereas at a speed of 160 km/h,it escalates to 143 ℃.This study can elucidate the mechanism underlying the impact of high-temperature airflow from the diesel engine outlet on the aerodynamic characteristics of diesel-engine-driven trains at various speeds on open tracks in high-altitude,low-pressure,and low-density environments.
关键词
内燃机车/高海拔/低气压/高温浮射流/数值仿真
Key words
internal combustion locomotives/high altitude/low pressure/high temperature buoyant jet/numerical simulation
维普
万方数据