An Investigation of Void Fraction in the Stratified/Annular Flow Regions in Smooth, Horizontal Tubes

Graham, D.M.; Kopke, H.R.; Wilson, M.J.; Yashar, D.A.; Chato, J.C.; Newell, T.A.

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Description

Title

An Investigation of Void Fraction in the Stratified/Annular Flow Regions in Smooth, Horizontal Tubes

Author(s)

• Graham, D.M.
• Kopke, H.R.
• Wilson, M.J.
• Yashar, D.A.
• Chato, J.C.
• Newell, T.A.

Issue Date

1999-01

Keyword(s)

• two-phase flow
• annular flow
• stratified flow
• intermittent flow
• horizontal gas-liquid flow
• void fraction

Abstract

Refrigerants R134a and R410A have been used for void fraction measurements in smooth horizontal tubes with diameters between 4mm and 7mm. Quality and mass flux were varied from 5% to 90% and 75 kglm2-s to 700 kglm2-s, respectively. Two test loops, one for condensing flows at 35C and the other for evaporating flows at 5C, were used in the investigation. Results show that near the transition from annular to stratified flow void fraction changed from viscousinertial dependence to gravitational-inertial dominated dependence. An important feature observed is the annular flow region's relative insensitivity to mass flux while the border region between annular and stratified flows is characterized by strong mass flux dependence.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center TR-144

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/11887

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 74

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