In order to study unsteady flowfield around high speed trains passing by ea
ch other, a three-dimensional inviscid numerical method based on three type
s of domain decomposition techniques is developed. Roe's FDS scheme is used
for the space discretization, and LU-SGS method is adopted for the time in
tegration. After validation of the code to a single track train/tunnel inte
raction problems with three dimensional tunnel configuration, the numerical
simulations of the trains passing by on the double-track are performed for
the 5 different cases using 3 basic parameters; e.g. nose shape, existence
of tunnel, and train length. After the parametric study, variational param
etric studies are carried out to understand the effects of the velocity of
the train, the gap between the train and the blockage ratio. Firstly, train
/tunnel interaction problems for double track railway system are investigat
ed and aerodynamics toads histories during the crossing events-train/train
interaction problem- are presented and discussed.