Numerical Simulation Of Hard Sleeper Train Indoor Air Distribution And Optimization Research Of Air Conditioning Modes

With the rapid development of railway enterprise, the train has become the main means of transport, but the thermal environment and air quality in the air-conditioned train can not meet the requirement of the passengers. For example, the distribution of temperature is uneven between each berth; passengers often feel bad symptoms, such as dry mouth, nasal congestion, dizziness, dry skin, irritability, etc. Air distribution is the decisive factor of influencing the indoor thermal environment and air quality. Therefore, this article will research on air distribution in the air conditioning train.A large number of research results show that the Standard k-ε turbulence model has been very mature, which is applied to study air distribution field in air conditioning train. On the basis of this conclusion, this article will regard YW25K air conditioning train as the research object, and use PHOENICS to simulate several typical turbulence models, and find a more reasonable model by comparing. Then, we will find a suitable grid method and iterations by simulating different meshing methods and iterations. It proved that the established mathematical physical model, the heat source condition and the selection of relaxation factor is reasonable and feasible by the way of experiments.Due to the complexity of the entire carriage model, large amount of calculation and time-consuming, this paper proposes a simplified method of simulation of a large space for the convenience of further research,which is to use the middle of the sleeper compartment to replace the entire carriage as the research object by adopting appropriate treatment of boundary conditions. It proved that the simplified method is reasonable and credible through the analysis.By simulating different air supply angles and different air supply and air return modes, then analysising the air distribution evaluation index of the typical cross section in different circumstances, it shows that the reasonable air supply angle is about40°,and each layer of berth upper supply and the ends of carriage return (Task Ambient Conditioning) is more reasonable.In this paper, the research results will provide important reference for improving the comfortable conditions and air quality in air-congditioned sleeper train.