Two-Phase Flow Development of R134a in a Horizontal Pipe: Computational Investigation

Mahmood, Raid A. and Saleh, Khalid and Musa, Veyan A. and Massoud, Enass and Sharifian-Barforoush, Ahmad and Abdulkareem, Lokman A. (2021) Two-Phase Flow Development of R134a in a Horizontal Pipe: Computational Investigation. International Journal of Heat and Technology, 39 (5). pp. 1532-1540. ISSN 0392-8764


Abstract

To improve the performance of vapor compression refrigeration systems that use vertical gravitational flash tank separators, the liquid separation efficiency of the vertical gravitational flash tank separator requires to be approved. To approach this improvement, the two-phase flow development and its behavior after the expansion device need to be investigated and predicted. For thus, this paper presents a three-dimensional computational investigation of the two-phase flow development of R134a after the expansion device in a horizontal pipe. Computational Fluid Dynamic (CFD) was used to predict the two-phase development and its behavior in the horizontal pipe. ANSYS 16.2 program was used to generates the geometry of the three-dimensional horizontal pipe of 2 meters long and 25 mm inner diameter. The hexahedral mesh was generated and it is assessed to obtain the optimum mesh size and number. Eulerian-Eulerian two-phase model was used with k-epsilon turbulence model. R134a was used as a working fluid in the horizontal pipe utilizing four different inlet diameters: 12, 12.5, 25, and 50.0 mm. Mass flux and vapor quality have been changed from 288 to 447 kg/m(2) .s and from 10 to 20% respectively. Results were validated against experimental results from the literature and revealed that the separation region length is affected by the initial phase velocities, inlet vapor quality, and inlet tube diameter. An empirical correlation to predict the expansion region length is proposed as a function of Froude, Webber, and Lockhart-Martinelli numbers.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Date Deposited: 13 Jan 2022 23:00
Last Modified: 19 Jan 2022 02:29
Uncontrolled Keywords: two-phase flow; R134a; computational fluid dynamic; expansion length; two-phase flow development; flow in a horizontal pipe
Fields of Research (2008): 09 Engineering > 0913 Mechanical Engineering > 091399 Mechanical Engineering not elsewhere classified
09 Engineering > 0913 Mechanical Engineering > 091307 Numerical Modelling and Mechanical Characterisation
Fields of Research (2020): 40 ENGINEERING > 4017 Mechanical engineering > 401706 Numerical modelling and mechanical characterisation
Identification Number or DOI: doi:10.18280/ijht.390515
URI: http://eprints.usq.edu.au/id/eprint/45460

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