Study On Uniformity Of Train Air Supply System And Air Distribution Optimization Of Car

In order to achieve uniformity of train air supply and rationality of compartment air distribution,this article systematic study the draft trunk of sleeping car and air distribution of compartment. The study includs the uniformity of air supply duct and pressure change, the distributing rules of sends air duct and inlet port, the several areas of air distribution of compartment affected by the air supply mode. The study combines theoretical calculation, CFD simulation and experiments, which effectively improve the efficiency , reduce the cost, and ensure the reliability of the results. The study conclusion has a certain significance for the ventilation design of real vehicleFirstly, using the calculation method of cross section uniform supply duct , this article makes detailed calculation on the rectangular openings size of simplified supply air duct . Then the simulation of the real vehicle air supply system is done. Because the complexity of the real vehicle air supply system, the theoretical results can not meet the uniformity requirements of air supply duct . The Simulation results show that Small amount wind in the front end of the air supply duct and large amount of wind in the back-end,so the method that adding baffles In the front end of the air duct is proposed. Through the simulation adjustment for the baffle height and rectangular aperture area, the unbalance rate of train compartment air flow is controlled in less than 10% finally.Secondly, outlet boundary conditions are usually set to uniform in the compartment airflow simulation formerly.This article put the actual equiblast method and uniform air supply method in comparison by simulation. The previous establishment method that outlet boundary conditions used is quite unreasonable. The actual compartment air distribution simulation shows that the persons foot wind speed of upper berth area is a little bigger.The simulation result can not meet the TB 1951-87 requirements of compartment micro wind speed. so the Optimization program is proposed. The temperature and velocity fields in compartment have greatly improved over the original by the Optimization program. Lastly, according to CFD simulation results of air supply system and compartment air distribution ,the experiment mockup is established by 1:1 proportion. The outlet velocity, air volume, air pressure and compartment temperature and velocity fields have been tested. By comparison, the CFD simulation results of air supply system is consistent with the experiment results and they are very close. The results basically satisfy the engineering demand. the results of temperature and velocity fields in compartment of the test and the simulation are very close, both of them can meet the railway standard. The results are evaluated by the indexes of ununiformity coefficient and Air Diffusion Performance Index (ADPI).