MODELING INCOMPRESSIBLE-FLOW IN A PRESSURE RELIEF VALVE

Lift, blowdown and discharge of pressure relief valves depend ultimate ly on the flow structures generated within those valves. A report is m ade of an enquiry into the incompressible flow structure within such a valve. Commercial software is used to predict axisymmetric flow patte rns inside a model of a real valve, and comparisons are made with the pressure distribution and force imposed on the real valve disc. The re liability of the simulation is further assessed using the oil-film tec hnique to record reattachment lengths of separated shear layers. Resul ts of the simulation are encouraging and have enabled flow regimes vis ible in the valve flow characteristic to be identified with the transi tion between separated flow patterns inside the valve.