In this work, a CFD model is developed to simulate the working of a 6mm diameter two-phase closed thermosyphon using water as the working fluid. At each section (evaporator, condenser, adiabatic) of the thermosyphon, lumped equations have been developed to calculate the temperatures at corresponding sections. In order to process two phase flow inside the system, a user-defined function (UDF) has been developed and integrated with the CFD model. The volume of fluid (VOF) method is used to carry out the simulations in Ansys FLUENT 15 and the lumped equations are solved in MATLAB 2013a. Volume fractions and temperature profiles obtained from CFD simulations and the lumped parametric estimations are found to be in good agreement with the experimental results available in literature. © Published under licence by IOP Publishing Ltd.

C. Balaji

Department of Mechanical Engineering

Y. Naresh

Capillary flow

Computational fluid dynamics

MATLAB

Siphons

THERMOSYPHONS

CFD simulations

LUMPED EQUATIONS

Numerical investigations

PARAMETRIC ESTIMATION

Temperature profiles

USER-DEFINED FUNCTIONS

Volume of fluid method

Working fluid

Two phase flow

Fulltext

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Numerical investigations of small diameter two-phase closed thermosyphon

Journal of Physics: Conference Series

In this work, the heat transfer performance of a two phase closed internally finned thermosyphon has been studied by both experimental and numerical investigations. The working fluid considered for the experiments is R134a, which is compatible with copper material and is environment friendly. The thermosyphon comprises an evaporator of length 200 mm, adiabatic length 100 mm and a condenser section 200 mm long. Rectangular cross section fins are placed internally along the length of the condenser. These are of constant area and are 5 mm wide and 1 mm thick. The fill ratios considered in this study are 20, 35, 50, 65 and 80%. Experiments are carried out for different cooling water mass flow rates of 10, 30, and 40 LPH. A lumped parameter model is developed to validate the experimental results, wherein the heat transfer equations are coupled with the mass transfer equations and the resulting equations are discretized explicitly. A boiling heat transfer coefficient correlation is developed with the experimental data to calculate the thermal resistance at the evaporator wall. The thermosyphon is tested between power levels of 25 and 150 W. The heat transfer performance of the R134a charged internally finned thermosyphon is found to be superior to that of a water charged thermosyphon. © 2018 Elsevier Masson SAS

International Journal of Thermal Sciences

Thermal performance of an internally finned two phase closed thermosyphon with refrigerant R134a: A combined experimental and numerical study

Fluid-Structure Interactions and Uncertainties

Fluid-Structure Interaction with Ansys/Fluent

Applied Thermal Engineering

CFD modelling of a two-phase closed thermosyphon charged with R134a and R404a

International Journal of Heat and Mass Transfer

Thermal characteristics of a closed thermosyphon under various filling conditions

Numerical modelling of the temperature distribution in a two-phase closed thermosyphon

Journal	Journal of Physics: Conference Series
Publisher	Institute of Physics Publishing
ISSN	17426588
Open Access	Yes