Numerical Simulation Of The Aerodynamic Behaviors Of Opposite High Speed Trains Crossing In The Crosswind

Crossing pressure pulse is an important aspect of evaluating the operation safety of trains. Air side force, air overturning moment and air yawing moment of a train are the parameters to measure the stability of trains in cross direction. Researching the forming causation of the crossing pressure pulse and the aerodynamic performance in cross direction is significant to the fast and safe running of trains. Finding out how train speed, crosswind speed and bridge structure influencing crossing pressure pulse and aerodynamic performance in cross direction is important too.In this thesis, CRH2 high speed train is selected as the researching object. The air turbulent flow field of two high speed trains crossing is numerically investigated by using the software CFdesign with the k-εtwo-equation model selected. Author uses the software ICEM CFD to mesh the calculating domain and the surface of trains to structured grid, and applies the moving grid generation technique in CFdesign for simulating the real crossing of two trains. According to these steps, author calculates two trains crossing at different train speed, crosswind speed or in different road conditions numerically.By analyzing the computing result theoretically, author finds out the relation between cross pressure pulse and train speed, knows how crosswind speed, bridge structure and the distance between centers of tracks changing crossing pressure pulse. Choosing air side force, air overturning moment and air yawing moment as parameters, author researches the stability of trains in cross direction in the course of two trains passing by each other, and gets out how train speed, crosswind speed and bridge structure influencing it. At last, author concludes the most dangerous time in the whole course of crossing in different kinds of running conditions and the particular act of the danger.