管路内を高速で移動する物体に作用する空気力

抄録

Aerodynamic force and moment acting on a body moving in a tube, where the blockage ratio is high and close to unity, play critical roles for the stability and performance of the tube-body system, such as a transportation system by a capsule, a high-speed train in a tunnel or a microgravity experiment facility consisting of a freely falling capsule and a braking tube. A series of preliminary experiments is carried out to determine the flow field confined by the tube inner wall and the body surface boundaries, using models of 18 mm in diameter having a blockage ratio 0.81 and the pressure difference 0.26 MPa between the upstream and downstream stations. The flow around the spindle-shaped body can be treated as an inviscid compressible fluid taking into account the boundary layer effect. The inclination of the body produced such a remarkable increase of the lateral force as has never been found for the body in an open-air flow condition.