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The study incorporates the time-dependent condensation model embedded in a porous medium with variations in liquid-vapor densities along with variable heat generation. A semi-implicit discretization is employed to convert the enthalpy based partial differential equations into a system of nonlinear algebraic equations. The dimensionless form of a two-phase model, along with the heat jump condition, is solved via an Adaptive Moving Mesh Method (AMMM), which uses a smooth enthalpy-temperature relationship. The unsteady liquid-vapor phase change front with internal heat variations are achieved with the manifestation of various appropriate parameters. The obtained results are elucidated graphically. Results indicate that the upsurge in internal heat generation is assisting to reduce the condensation liquid-vapor phase front. With the enormous time variations, the condensation front position is found to be maximum as compared to a short time variation. The study further indicates that liquid density, liquid thermal conductivity, and temperature have enhanced the position of the liquid-vapor front with the variations in dimensionless time.


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Analysis of unsteady liquid-vapor front in a porous medium with variable heat generation

Show Author's information Zafar Hayat Khan1,2( )Rashid Ahmad3Licheng Sun1Waqar Ahmed Khan4
State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China
Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084, China
Melbourne Graduate School of Education, University of Melbourne, 234 Queensberry Street, Melbourne, Victoria 3010, Australia
Department of Mechanical Engineering, College of Engineering, Prince Mohammad Bin Fahd University, Al Khobar 31952, Saudi Arabia

Abstract

The study incorporates the time-dependent condensation model embedded in a porous medium with variations in liquid-vapor densities along with variable heat generation. A semi-implicit discretization is employed to convert the enthalpy based partial differential equations into a system of nonlinear algebraic equations. The dimensionless form of a two-phase model, along with the heat jump condition, is solved via an Adaptive Moving Mesh Method (AMMM), which uses a smooth enthalpy-temperature relationship. The unsteady liquid-vapor phase change front with internal heat variations are achieved with the manifestation of various appropriate parameters. The obtained results are elucidated graphically. Results indicate that the upsurge in internal heat generation is assisting to reduce the condensation liquid-vapor phase front. With the enormous time variations, the condensation front position is found to be maximum as compared to a short time variation. The study further indicates that liquid density, liquid thermal conductivity, and temperature have enhanced the position of the liquid-vapor front with the variations in dimensionless time.

Keywords: numerical solution, porous medium, liquid-vapor front, heat generation, condensation rate

References(19)

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Publication history
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Acknowledgements

Publication history

Received: 06 August 2020
Revised: 24 September 2020
Accepted: 21 October 2020
Published: 08 January 2021
Issue date: September 2022

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© Tsinghua University Press 2020

Acknowledgements

The current work is supported by the National Natural Science Foundation of China (Grant Nos. 12075160 and 52076144).

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