Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

An Investigation of Refrigerant Void Fraction in Horizontal, Microfin Tubes

Published

Author(s)

David A. Yashar, M J. Wilson, HM R. Kopke, D M. Graham, J C. Chato, TJD A. Newell

Abstract

A series of experiments to determine void fraction in both condensation and evaporation have been performed in horizontal microfin tubes with refrigerants R134a and R410A. Mass flux varied from 75 kg/m2-s to 700 kg/m2-s and average test section quality varied from 5 percent to 80 percent. Zero degree (axial grooving) and 18 degree helix microfin tube configurations have been examined in both condensation and evaporation. Four tubes were examined (7.3mm and 8.9mm diameters with axial and 18 degree helix angle microfins). Evaporation and adiabatic conditions in microfin tubes generally show similar void fraction trends found in smooth tubes. Condensation results for microfin tubes show a lower void fraction than smooth tubes.
Citation
Hvac&R Research

Keywords

condensation, evaporation, microfin tube, microgroove tube, refrigerant, two-phase flow, void fraction

Citation

Yashar, D. , Wilson, M. , Kopke, H. , Graham, D. , Chato, J. and Newell, T. (2001), An Investigation of Refrigerant Void Fraction in Horizontal, Microfin Tubes, Hvac&R Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860827 (Accessed December 26, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created January 1, 2001, Updated February 19, 2017