Numerical Optimization Of Uniform Air Supply In High Speed Train Air Supply Duct

As China’s railway passenger cars enter the era of high-speed development,passengers no longer only focus on speed,but also pay more attention to the comfort of trains.The key to improving train comfort lies in improving the air quality of train carriages,making the air flow organization of train carriages reasonable and in line with human comfort indicators.To achieve this goal,it is necessary to design the air ducts of high-speed trains reasonably to ensure that the air volume at the air outlets of high-speed trains is as uniform as possible in the main and side air ducts.Based on extensive literature and CAD drawings on high-speed trains,a 1:1 air conditioning supply duct model for high-speed trains was established using SOLIDWORKS and simulated using FLUENT.Simulation calculations were conducted on the initially designed air supply duct under three different air volume conditions,observing the velocity vector diagram of the duct,analyzing the impact of different air volumes on the wind speed changes inside the duct,obtaining the air volume of each outlet of the main and side air ducts,and then analyzing the impact of different air supply volumes on the air volume at the outlet.Research has found that the larger the air supply volume,the more significant the change in airflow velocity in the air duct.According to relevant regulations,the wind speed in the air duct of the train air conditioning system should not exceed 7 m/s.But when the air supply volume is too large,the wind speed in the air duct is already greater than 7 m/s,which generates a lot of noise in the air supply duct and affects the service life of the high-speed train air conditioning system.The study also found that the air volume at the air duct outlet is uneven,with the larger the supply air volume,the more uneven the output air volume.Considering the above reasons,the paper optimizes the main and side air ducts.The optimization measure for the main air duct is to add a semi circular wind deflector after the air outlet position with low air volume.For the supply side air duct,increase or decrease its air outlet area based on the amount of air output from each air outlet.Establish a physical model containing the interior environment of the carriage using SOLIDWORKS,simulate and analyze the flow field model of the carriage under three different air flow conditions,select four sections of the carriage,observe their velocity vector maps and velocity cloud maps before and after optimization,to verify the feasibility of the optimization measures.Comparing the optimized airflow distribution in the front and rear compartments under different air supply conditions,it was found that:It is feasible to improve the uniformity of air flow at the outlet of the high-speed train air supply duct by adding wind deflectors and increasing or reducing the area of the air outlet in the air supply duct.After taking reasonable optimization measures for the air supply duct,it can greatly improve the organization and distribution of air flow inside the carriage,making the air flow speed inside the carriage comply with relevant standards in the International Union of Railways.