Aerodynamic vibration of combined rigid bodies due to leakage flow (the effect of body shapes and support condition)

We carried out experiments using a model equipment composed of combined rigid bodies and a tunnel wall which forms leakage flow channel in order to simulate the aerodynamic oscillations of high speed train observed in a tunnel section, and examined the relationship between the instability and the effect of such parameters as head shapes of both leading and trailing car bodies, equilibrium position and so on. As a result of the experiment, minute vibration with yawing mode and two types of unstable phenomena were observed in the specific flow velocity region. Especially, head shape of trailing car body, clearance between the tunnel and car bodies and equilibrium position were found to be major factors that have a large effect on the instability.