41 research outputs found
Aerodynamic Characteristics of Individual Ballast Particle by Wind Tunnel Tests
Ballast flying has been considered as a problem in train aerodynamics with increasing the maximal speed. And this
phenomenon seriously threats the safety of train operation. However, aerodynamic characteristics of individual ballast
were less studied in the previous literature. This paper describes an investigation of the aerodynamic effect of ballast
particles by wind tunnel tests. It considers the nature of the wind and ballast physical characteristics. A simple method for
calculating the wind effects by CFD is set out, ballast particles were classified according to their shapes and mass in order
to investigate the influence of the wind velocity, wind pressure and other parameters on displacement of ballast particles.
Two sets of wind tunnel tests were performed under the conditions that ballast particles were movable and unmovable on
the platform respectively. The tests data and reasonable explanations were given, as well as the CFD simulations of
individual ballast particles