scholarly journals Experimental Investigation of the Vertical Upward Single- and Two-Phase Flow Pressure Drops Through Gate and Ball Valves

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Ammar Zeghloul ◽  
Hiba Bouyahiaoui ◽  
Abdelwahid Azzi ◽  
Abbas H. Hasan ◽  
Abdelsalam Al-sarkhi
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Single Phase ◽  
Gate Valve ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

Abstract This paper presents an experimental investigation of the pressure drop (DP) through valves in vertical upward flows. Experiments were carried out using a 1¼″ (DN 32) ball and gate valve. Five opening areas have been investigated from fully open to the nearly fully closed valve, using air with a superficial velocity of 0–3.5 m/s and water 0.05–0.91 m/s. These ranges cover single-phase and the bubbly, slug and churn two-phase flow regimes. It was found that for the single-phase flow experiments, the valve coefficient increases with the valve opening and is the same, in both valves, for the openings smaller than 40%. The single-phase pressure drop increases with the liquid flowrate and decreases with the opening area. The two-phase flow pressure drop was found considerably increased by reducing the opening area for both valves. It reaches its maximum values at 20% opening for the ball valve and 19% opening for the gate valve. It was also inferred that at fully opening condition, the two-phase flow multiplier, for both valves, has been found close to unity for most of the tested flow conditions. For 40 and 20% valve openings the two-phase multiplier decreases in the power-law with liquid holdup for the studied flow conditions. Models proposed originally for evaluating the pressure drop through an orifice in single-phase and two-phase flows were also applied and assessed in the present experimental data.

Single Phase and Two-Phase Flow Pressure Drop in Pebble Beds

2010 ◽  
Author(s):  
Bofeng Bai ◽  
Maolong Liu ◽  
Xiaofei Lv ◽  
Wang Su ◽  
Xiao Yan ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Gas Phase ◽  
Single Phase ◽  
Two Phase Flow ◽  
Particle Diameter ◽  
Spherical Particles ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

An experimental study was conducted on the pressure drop of single phase and air-water two-phase flow in the bed of rectangular cross sections filled with uniform spheres densely. In the present flow-regime model, the bed was subdivided into a near-wall region and a central region. And a new empirical correlation for the prediction of single-phase flow pressure drops was proposed based on the model. The correlation can be used to predict the single phase pressure drop for both great tube-to-particle diameter ratio packed beds and small tube-to-particle diameter ratio packed beds and for the pebble beds packing with spherical particles and non spherical particles. A new empirical correlation for the prediction of two-phase flow pressure drops was proposed based on the gas phase relative permeability as a function of the gas phase saturation and the void fraction. The correlation fit well also for both experimental data points of spherical particles and non spherical particles.

Two-Phase Flow Pressure Drop Measurement in PEM Fuel Cell Flow Channels

2014 ◽  
Author(s):  
Mehdi Mortazavi ◽  
Kazuya Tajiri
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Two Phase Flow ◽  
Pem Fuel Cell ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Channels ◽  
Mass Fluxes ◽  
Flow Pressure

Proton exchange membrane (PEM) fuel cells produce power with water and heat as inevitable byproducts. Accumulated liquid water within gas channel blocks the reactant flow and cause pressure drop along the gas channel. It is of extreme importance to accurately predict the liquid and gas two-phase flow pressure drop in PEM fuel cell flow channels. This pressure drop can be considered as an in-situ diagnostic tool that reveals information about the amount of liquid water accumulated within the flow channels. In this paper, the two-phase flow pressure drops are measured in ex-situ PEM fuel cell parallel flow channels. The pressure drops were measured for air mass fluxes of 2.4–6.3kg/m2s and water mass fluxes of 0.0071–1.28kg/m2s. These mass fluxes correspond to 2–5.33m/s and 7.14 × 10−6 – 0.0012m/s air and water superficial velocities, respectively. The measured two-phase flow pressure drops are then compared with different two-phase flow pressure drop models. Qualitative and quantitative comparison between the experimental results and existing models is provided in this work.

Single-Phase and Two-Phase Flow Through Thin and Thick Orifices in Horizontal Pipes

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Manmatha K. Roul ◽  
Sukanta K. Dash
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Operating Conditions ◽  
Orifice Diameter ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Horizontal Pipes ◽  
Flow Through

Two-phase flow pressure drops through thin and thick orifices have been numerically investigated with air–water flows in horizontal pipes. Two-phase computational fluid dynamics (CFD) calculations, using the Eulerian–Eulerian model have been employed to calculate the pressure drop through orifices. The operating conditions cover the gas and liquid superficial velocity ranges Vsg = 0.3–4 m/s and Vsl = 0.6–2 m/s, respectively. The local pressure drops have been obtained by means of extrapolation from the computed upstream and downstream linearized pressure profiles to the orifice section. Simulations for the single-phase flow of water have been carried out for local liquid Reynolds number (Re based on orifice diameter) ranging from 3 × 104 to 2 × 105 to obtain the discharge coefficient and the two-phase local multiplier, which when multiplied with the pressure drop of water (for same mass flow of water and two phase mixture) will reproduce the pressure drop for two phase flow through the orifice. The effect of orifice geometry on two-phase pressure losses has been considered by selecting two pipes of 60 mm and 40 mm inner diameter and eight different orifice plates (for each pipe) with two area ratios (σ = 0.73 and σ = 0.54) and four different thicknesses (s/d = 0.025–0.59). The results obtained from numerical simulations are validated against experimental data from the literature and are found to be in good agreement.

scholarly journals Study Pressure Drop for Two-Phase Flow in a Large Diameter Tube

2019 ◽  
Vol 17 (72) ◽  
pp. 101-109
Author(s):  
Muhsen Koli Nahi
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Homogeneous Model ◽  
Large Diameter ◽  
Horizontal Tube ◽  
Phase Flow ◽  
Water Mixture ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Pressure

The aim of this study is to discover the deviation of two phase flow correlations. A comparsion was made between the expermital values of two-phase flow pressure drops data were obtained experimentally by Al-Jumaily (1999) by using air-water mixture in a horizontal tube of (132 mm) nominal diameter and a test section of (32 m) long at pressure and temperature close to atmospheric and those predicted by three correlations well-used in the literature, which show that the homogeneous model was the best

Correlations for predicting single phase and two-phase flow pressure drop in pebble bed flow channels

2011 ◽  
Vol 241 (12) ◽  
pp. 4767-4774 ◽  
Author(s):  
Bofeng Bai ◽  
Maolong Liu ◽  
Xiaofei Lv ◽  
Junjie Yan ◽  
Xiao Yan ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Pebble Bed ◽  
Two Phase ◽  
Flow Channels ◽  
Flow Pressure

Experimental investigation of pressure drop in failed Electrical Submersible Pump (ESP) under liquid single-phase and gas-liquid two-phase flow

2021 ◽  
Vol 198 ◽  
pp. 108127
Author(s):  
William Monte Verde ◽  
Jorge Biazussi ◽  
Cristhian Estrada Porcel ◽  
Valdir Estevam ◽  
Alexandre Tavares ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Submersible Pump ◽  
Two Phase ◽  
Electrical Submersible Pump

Asymptotic Generalizations of the Lockhart-Martinelli Method for Two Phase Flows

2009 ◽  
Author(s):  
Y. S. Muzychka ◽  
M. M. Awad
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Point Of View ◽  
Phase Flow ◽  
Pressure Gradients ◽  
Two Phase ◽  
Interfacial Pressure ◽  
Phase Liquid ◽  
Flow Pressure

The Lockhart-Martinelli method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modelling. Comparisons are made with the Lockhart-Martinelli method, the Chisholm method, and the Turner-Wallis method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modelled for each type of flow regime such as: bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminer, turbulent-turbulent, laminar-turbulent and turbulent-laminar flow regimes proposed by Lockhart and Martinelli.

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