Frictional pressure drops of two-phase R-134A flow in horizontal and vertical U-type wavy and straight tubes

Ing Youn Chen*, Yu Shi Wu, Yu Juei Chang, Chi-Chuan Wang

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This study presents the measurements of R-134a two-phase frictional pressure gradient subject to vertical and horizontal arrangements of a U-type wavy tube with inner diameter of 5.07 mm and a curvature ratio of 5. The ratio between two-phase pressure gradients of U-bend and straight tube is about 2.5 - 3.5. For the straight tube, the frictional two-phase pressure gradient ratio between the vertical and horizontal arrangements is marginally higher (1.0 - 1.2) for annular flow pattern at x > 0.5, and is 1.0 - 1.4 for the U-bend in the wavy tube. The higher resistance in the vertical arrangement is due to the buoyancy force against the flow inertia. However, for x < 0.5, this ratio is gradually increased due to the difference of flow pattern. The ratio is increased to 1.8 in the straight tube. For the U-bend, the ratio is 2.1 for flow entering the upper tube and is 1.5 for flow entering the lower tube at x = 0.1 and G = 200 kg/m2.s. For the vertical wavy tube, additional effects like the flow pattern transition, liquid flow reversal, and freezing slug may cause additional pressure drops.

Original languageEnglish
Title of host publicationProceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006 - Fluids Engineering Division
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Print)0791837904, 9780791837900
DOIs
StatePublished - 1 Jan 2006
Event2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006 - Chicago, IL, United States
Duration: 5 Nov 200610 Nov 2006

Publication series

NameAmerican Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED
ISSN (Print)0888-8116

Conference

Conference2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006
CountryUnited States
CityChicago, IL
Period5/11/0610/11/06

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    Chen, I. Y., Wu, Y. S., Chang, Y. J., & Wang, C-C. (2006). Frictional pressure drops of two-phase R-134A flow in horizontal and vertical U-type wavy and straight tubes. In Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006 - Fluids Engineering Division (American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/IMECE2006-13247