180°曲がり管内の脈動流れ

抄録

A pulsating flow has been studied experimentally, because of its practical importance in the mechanical engineering (e.g.,intake-exhaust systems of the engine and the industrial piping). It is very useful to investigate such an unsteady flow experimentally for improvement of mechanical efficiency. The present experiment is conducted to clarify a flow state of the pulsating flow with a period T=0.2sec in the 180° curved pipe. We measured the wall static pressure, wall shear stress and distributions of axial flow velocity respectively. The pressure gradient shows favorite pressure gradient during the acceleration to the deceleration phase and it forms the adverse pressure gradient near the phase of valve closing. The wall shear stress shows a spiking peak just after opening the valve. The distribution of the axial flow velocity shows the flow maintained constant, and then the fast flow is shifted to the outside which is affected by the centrifugal force.