The onset of liquid entrainment during discharge from two branches on an inclined wall

Abstract

A theoretical investigation has been conducted for predicting the critical liquid height at the onset of liquid entrainment during dual discharge from a stratified two-phase region through branches mounted on an inclined flat wall. The centerlines of the two branches are parallel and they fall in a common vertical plane. Two models have been developed; a simplified point-sink model and a more-accurate finite-branch model. Predictions from the two models are shown to be in good agreement for the condition of high flow rates from the branches, while the finite-branch model is necessary for accurate predictions at low branch flow rates. This behaviour has been confirmed experimentally for the vertical-wall configuration.On a effectue une recherche theorique afin de predire la hauteur critique du liquide au commencement de l'entrainement du liquide lors de la double decharge d'une region biphasique stratifiee dans des branches montees sur une paroi plane inclinee. Les axes des deux branches sont paralleles et tombent dans un plan vertical commun. Deux modeles ont ete mis au point : un modele de puits ponctuel simplifie et un modele a branches finies plus precis. On montre que les predictions des deux modeles concordent bien pour de forts debits des branches, tandis que le modele a branches finies est necessaire pour des predictions precises a de faibles debits des branches. Ce comportement est confirme exp6rimentale-ment pour la configuration a paroi verticale.

The onset of gas pull-through during dual discharge from a stratified two-phase region: Theoretical analysis

“…The reported theoretical investigations for the present problem are essentially related to the prediction of the onset of liquid entrainment during either single or dual discharge from a large stratified region (e.g., Maier et al; 12 Soliman and Sims; 13 Hassan et al 14 ). For the theoretical prediction of the critical height at the onset of gas entrainment, the only study available in the literature, to the authors' best knowledge, was done by Ahmed et al 15 and is related to single discharge through a side branch of finite diameter from a stratified two-phase region.…”

Theoretical Analysis of the Onset of Gas Entrainment from a Stratified Region through a Single Side‐Oriented Branch at Moderate Froude Numbers

“…The previously reported theoretical investigations for the present problem are essentially related to the prediction of the onset of liquid entrainment, during either single or dual discharge from a large stratifi ed region (e.g., Soliman and Sims, 1992;Hassan et al, 1999;Maier et al, 2001). The objective of the present analysis is to investigate the phenom-enon of the onset of gas entrainment at moderate values of Fr (>1).…”

“…Hassan (1995) further broadened the experimental research conducted on this problem, by investigating the onsets of gas and liquid entrainment, as well as two-phase mass fl ux and quality during single, dual, and triple discharge through small branches from a large, stratifi ed, twophase region. The previously reported theoretical investigations for the present problem are essentially related to the prediction of the onset of liquid entrainment, during either single or dual discharge from a large stratifi ed region (e.g., Soliman and Sims, 1992;Hassan et al, 1999;Maier et al, 2001). The objective of the present analysis is to investigate the phenomenon of the onset of gas entrainment at moderate values of Fr (>1).…”