Abstract
A basic study of flow controls using jets was conducted to reduce an unsteady aerodynamic force acting on a train in tunnels. We installed air jet devices around a model car in the wind tunnel and measured pressure fluctuations on the side of the vehicle. The results shows a) jets allow to reduce pressure fluctuations, b) it is effective to jet air horizontally at the lower side of the car facing the tunnel wall, and c) the reduction rate of the pressure fluctuations may be relate to the square of the rate of the jet speed to the train speed.
