Experimental investigation of two-phase discharge from a stratified region through a small branch mounted on an inclined wall

Experimental data are presented for the mass flow rate and quality of two-phase discharge through a small branch of diameter d (=6.35 mm) attached normally to an inclined flat plane. The flat plane was situated in a large tank containing a stratified mixture of air and water under pressure (316 kPa) and at room temperature. The plane was inclined through various angles (θ) in increments of 30°, from the outlet-branch orientation being vertically upward through the horizontal to vertically downward. The bulk of the data correspond to seven inclination angles and two test-section-to-separator pressure differences (ΔP) of 11.0 and 115.5 kPa, and for each combination of θ and ΔP, the mass flow rate and quality were measured at different values of the interface level (h) between the onsets of gas and liquid entrainment. Four additional data sets were generated for other values of ΔP in order to confirm certain trends. Influences of these independent variables on the mass flow rate and quality are discussed and normalized plots are presented showing that the data can be collapsed for a wide range of conditions. Comparisons are made between the present data and previous correlations/models and new empirical correlations are formulated and shown to be capable of predicting the present data with good accuracy.