The Numerical Simulation And Research On High-speed Train Aerodynamic Effect

As the high-speed train speed increasing, a series of train aerodynamic effect problem appears. Among them, the trains passing each other open wire, tunnel passing and tunnel through, in the three kinds of typical working conditions, train outside of the aerodynamic effect is most obvious, and it will transfer to the train compartment, aerodynamic effect research outside the characteristics of fluctuation and to explore the inhibition of external pressure fluctuations affect the car compartment pressure method is to study the main line of this article.Intense pressure fluctuations on the surface of the main train into and out of the train tunnel and other produce, outside pressure fluctuation is mainly through the inlet and outlet of the air conditioning system and the gap into the passenger compartment, affect the ride comfort of passengers.So to prevent pressure wave is introduced into classroom, both must have a good body sealing, also need to research the train air conditioning and ventilation system for car air pressure fluctuations incoming delay inhibition and protection strategy of passenger compartment pressure inside the car.There are two aspects in the research content in this paper, the first commercial application of fluid analysis software Fluent to simulate the train tunnel by passing each other, and open wire passing three typical working condition, analyzes the different speed level under the train aerodynamic effect characteristics of surface and its nearby area, different position of a car body on both sides of the curve of pressure fluctuations, thus learn at different speed and different marshalling the influence of pressure on the surface of a train.The results show that the train in the working condition of tunnel intersection pneumatic effect is most obvious, the tunnel intersection of variable cross section in the process of negative pressure amplitude reached more than 9 kpa.Then on the basis of the calculation result of numerical simulation and real vehicle test data as a verification, according to the type CRH2 train ventilation system to send the working principle of the exhaust air and pressure protection device. Using the new type of one-dimensional fluid simulation software flowmaster, set up the new type of pressure protection control method simplified model of ventilation system, by comparing the current pressure protection device and used in the new protection scheme, the simulation results show that using dual motor inverter frequency conversion control into the exhaust pressure protection way relative to the original single motor inverter synchronous control into the exhaust has better adaptability and reliability of pressure protection.For the analysis,this paper is based on real vehicle experiment data, applying numerical simulation and one dimensional simulation software to analyze and evaluate the pressure fluctuation of high-speed train from inner to outer and the method is feasible, and based on the unsteady aerodynamic effect of the train under the condition of inside and outside research, by train, both inside and outside pressure fluctuation characteristics of typical working conditions, air conditioning and ventilation system for the future analysis reference for the optimization design.