Abstract
With the increasing speed and lightening body of train, the interaction of high-speed train and air becomes more and more important. If the interaction increases the forces acting on the train, disastrous results such as overturning and derailment will be brought out. While because of the difference of research methods between vehicle system dynamics (VSD) and aerodynamics for a long time, they were studied as two independent systems individually. In the study of VSD, Lagrangian system of coordinates was usually used and in aerodynamics Eulerian system was adopted to. This makes it impossible to research the coupling interaction between high-speed train and air because when the structure moved, the material coordinates moved from its initial position to a new position, but the space coordinates were still in its initial position in Eulerian coordinates. In order to research the coupling interaction between high-speed train and air, a numerical method Arbitrary Lagrangian-Eulerian Method (ALE) is presented to analyze the train and air interaction problems in this paper. In ALE, the computational fluid dynamics (CFD) based on finite volume method is applied to compute the unsteady forces acting on the train. A program based on the vehicle-track coupling dynamics is used to simulate the dynamical response of the vehicles resulted from aerodynamic loads and rail irregularities. By exchanging information between CFD and VSD in due time, the moving boundary between train and air is deal with and co-simulation was realized. At last, the coupling interaction between train and air were studied in detail based on ALE.
