증기밸브 주위를 지나는 유동특성에 관한 수치해석적 연구

A control valve is one of the flow devices most frequently employed in pipeline system, but the gas flow passing through it is hardly known since the flow is subject to extremely complicated, unsteady, and 3- dimensional phenomena. Under a certain condition, the flow is choked at a minimum area of valve and strong flow oscillation occurs inside the valve. For the safe operation and lower maintenance cost of pipeline system, the flow characteristics around control valve should be fully understood. In the present study, a computational work has been made to investigate the flow characteristics passing through a system control valve. The 3- dimensional compressible Navier-Stokes equations have been solved using a fully implicit finite volume scheme. It is found that the oscillation is associated with the rotational flow motions which occur the passage between the valve and valve seat. The present results shows that this oscillation strongly depends on mass flow rate and valve opening.