Void Fraction and Pressure Drop in Microchannels

Payne, W.T.

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https://hdl.handle.net/2142/12005 Copy

Description

Title

Void Fraction and Pressure Drop in Microchannels

Author(s)

Payne, W.T.

Contributor(s)

• Nino, V.G.
• Hrnjak, P.S.
• Newell, T.A.

Issue Date

2000-12

Keyword(s)

• void fraction
• pressure drop
• microchannels

Abstract

"An experimental investigation of pressure drop and void fraction in aluminum microchannel tubes was conducted for a variety of flow conditions. Primary fluids of interest are refrigerants, R134a and R41OA. The microchannel tubes are square port geometries with hydraulic diameters of 0.91 and 1.35 mm for test section lengths of 61 and 107cm (24"" and 42""). The test matrix encompasses the entire quality range from 0-1, mass fluxes from 75 kglm2s to 350 kglm2s, and 3 temperatures from 10 to 35 DC. Test sections are adiabatic and in a horizontal orientation. Single-phase and two-phase pressure drop data were taken. No ""small-tube"" effects due to the hydraulic diameter were found for single-phase frictional pressure drop. Two-phase pressure drop was found to be mass flux dependent. A change in pressure drop behavior as mass flow rates increased beyond a set value is caused by a two-phase flow regime transition. Available pressure drop correlations tend to consistently overpredict the experimental pressure drop. A new microchannel testing facility was constructed at the University of Illinois at Urbana-Champaign. Details on system design, components, and operation are given."

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-178

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/12005

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 107

Owning Collections