2-Dimensional Analysis Of Discharge Flow Of High-Pressure Saturated Water From Orifices

High-pressure saturated water discharge from orifices (I.D. 17 mm and 30 mm) in a pipe (I.D. 127 mm) is analyzed by using a transient, nonequilibrium, two-dimensional two-fluid model. The numerical results are compared with experimental data. These results depict flow patterns which affect the discharge rate, such as a flow contraction in the orifice and a water jet from the orifice with flashing around the peripheral region of the jet. The predicted discharge rate is within the observed data scatter of 15% when the pressure difference across the orifice is over 2.5 MPa, while the prediction is underestimated by 20% when the pressure difference is about 1.0 MPa.