Aerodynamics Performance Of High-speed Train On Cutting

High-speed transport is the development direction of modern railway. With the development of high speed railway and train speed, interaction between train and air fluctuates violently. A series of aerodynamic problems deteriorating running safety demand a prompt solution. The typical railway environment includes the embankment, high bridge, tunnel, cutting and so on. In order to study such problem, the thesis combines aerodynamics and multi-body system dynamics to study the performance of high speed trains in basis aerodyanmics, aerodynamics in crosswinds and aerodyanmics by pass each other.Based on the the 3-D steady and incompressible Navier-Stokes equation, and standard k-εturbulence model, this thesis establishes a dynamic simulation model of high-speed trains with CFD software FLUENT, besides, the high-speed train dynamics model is established by SIMPACK based on the theory of vehicle dynamics. The aerodyanmics forces ia added to the dynamics modle and the performance is calculated with the effect of aerodynamic forces.Firstly, when the high-speed train passes the cutting, the aerodynamic forces and pressure distribution are analyzed. Besides, the high-speed train aerodynamic forces of the cutting and flat ground are compared. Secondly, the high-speed train model passing the half cutting under crosswind is established. And the high-speed train aerodynamic forces under different wind angle, different train running velocity and diffent wind velocity are researched. Besides, the influences on aerodynamic forces of cutting's gradient when high-speed train passes the cutting under crosswind are researched.At last, the high-speed train models of passing event are established. The varations of aerodynamic forces are discussed. So the safety indexes of the coefficient of derailment, rate of wheel load reduction, lateral force of wheel axle and vertical force of wheeltrack are calculated. The differences of high-speed train aerodynamic forces and dynamics between the cutting and flat ground are compared and analyzed. The results could provide reference to the resaonable design of high-speed railway.