Numerical Simulation Flow Characteristics Of High Speed Train Equipment Cabin In Wind-Sand Environment

Train aerodynamics in the violent wind-sand environment has become one of the important factors which affect the development of high-speed railway, and the development of high-speed railway in the west of China and even in the world.Severe environmental problems can seriously affect the performance and safety of equipment, such as damage to components of electrical equipment, performance degradation of insulating materials. Regarding to the Lanzhou-Xinjiang High-speed Railway exposing in abominable natural environment, especially violent wind-sand environment, research on the analysis of train operation and ventilation performance of equipment compartment and flow characteristic within equipment compartment has significant meaningsFirst of all, preliminary work of this paper is based on cooperative project(performance and improvement of ventilation dust-extraction unit of equipment compartment CRH5H-type high and cold and wind-sand resistance motor train unit) with Changchun Railway Vehicle Co., Ltd. It deepens and continues to research flow characteristic within equipment compartment, adopting computational fluid dynamics(CFD) technology, performing modeling to equipment compartment of train and having coupling with CRH5G-type motor train unit, and researching flow characteristic of outside and inside train equipment compartment of stable operation and high-wind operation under different vehicle speed and different wind speed.Secondly, it studies flow characteristic of equipment compartment of train in wind-sand environment. It firstly starts from basic theory of fluid dynamics, introducing research method of gas-solid two-phase flow and research status at home and broad to wind-drift sand, train equipment compartment and ventilating grill. Inside and outside flow of gas-solid two-phase flow at train body and equipment compartment belongs to complex turbulence flow. It introduces frequently-used turbulence model at the same time, analyzing and affirming to adopt standard SST turbulence model as simulation for gaseous phase flow, choosing to use discrete particle track model based on coordinate system of Euler Lagrange as simulation for solid phase flow.Through verification to grilling of V-V type and semicircle-pipe filter, affirm and verify to agree with the computational method. In calculation, it analyzes flow characteristic of outside and inside equipment compartment of CRH5G-type motor train unit under stable operation(wind-sand environment) and high wind environment operation, analyzing distribution character of velocity field and pressure field of first-train equipment compartment, representing velocity vector figure, velocity scroll integrogram, stress cloud picture, distribution diagram of inside and outside flow figure of equipment compartment and movement collision inside and outside solid phase particle of equipment compartment and particle track change features. It analyzes sand grain(at subgrade, track, bottom of train, nearby equipment compartment and place before and after train) deposition feature.Finally, it mainly analyzes pressure at both sides of equipment compartment of different location(train head, medium train and train end) and different vehicle speed under steady state and distribution feature of velocity, pressure and distribution feature of velocity of windward side and leeward side of train equipment compartment at different locations under huge wind-sand environment. Apart from these it analyzes ground effect and impact of different wind speed on inside and outside inflow of equipment compartment. Under a steady environment, velocity range of the inflow velocity for train operating equipment cabin is 0~3m/s, 40m/s in the cross wind flow velocity amplitude range 7~15m/s, decreasing 2~4m/s when considering atmospheric boundary layer. Research method and conclusion are expected to provide beneficial reference for subsequent research and work.