Prediction of Single- and Two-Phase Flow Contraction through a Sharp-Edged Short Orifice

Abstract

The predictions of a new model for the contraction coefficient of single-and two-phase flows through a sharp-edged short orifice are checked against data recently obtained with water, air, and air/water mixture flows. The model includes all relevant primary design parameters. The predictions are validated for a wide range of conditions and physical properties typically encountered in industrial fluid-dynamic systems. Calculations based on the new model are sufficiently accurate for engineering purposes. Reasonable extrapolations to other test conditions with an acceptable accuracy can be expected.

Stability of gas pressure regulators

“…Comparing the flow area from the test data with the actual hardware hole size indicates that we need to use a coefficient for the area contraction of 0.877. This value for the flow coefficient due to the effect of vena contracta corresponds well to typical published values between 0.73 and 0.97, depending on the shape of the opening [17]. For our linear model, Eq.…”

Vertically upward two-phase flow with a highly viscous liquid-phase in a nozzle and orifice plate

“…Single-phase, orifice plate flows have a flow area that is considerably smaller than the orifice plate area. In twophase flows this contraction only occurs at very low and very high qualities (Shannak et al, 1999). For the range of qualities obtained here, the minimum flow area can be taken as the orifice plate area.…”