Abstract
Lateral vibrations of high-speed trains increase in tunnels by aerodynamic force whose mechanism is unknown. To investigate this aerodynamic force and develop its measures, a numerical simulation and a wind tunnel test were conducted. The numerical simulation revealed the mechanism of the generation of the unsteady aerodynamic force. Considering the mechanism, installing fins under the car body and rounding the lower corners of the body were designed to reduce the aerodynamic force. The wind tunnel test confirmed their effectiveness.
