Thermal Modeling of Unlooped and Looped Pulsating Heat Pipes

2001 ◽  
Vol 123 (6) ◽  
pp. 1159-1172 ◽  
Author(s):  
Mohammad B. Shafii ◽  
Amir Faghri ◽  
Yuwen Zhang
Keyword(s):  
Heat Transfer ◽  
Finite Difference ◽  
Heat Pipes ◽  
Analytical Models ◽  
Charge Ratio ◽  
Sensible Heat ◽  
Governing Equations ◽  
Heating Wall ◽  
Heat Mode ◽  
Explicit Finite Difference

Analytical models for both unlooped and looped Pulsating Heat Pipes (PHPs) with multiple liquid slugs and vapor plugs are presented in this study. The governing equations are solved using an explicit finite difference scheme to predict the behavior of vapor plugs and liquid slugs. The results show that the effect of gravity on the performance of top heat mode unlooped PHP is insignificant. The effects of diameter, charge ratio, and heating wall temperature on the performance of looped and unlooped PHPs are also investigated. The results also show that heat transfer in both looped and unlooped PHPs is due mainly to the exchange of sensible heat.

Thermal Modeling of Unlooped and Looped Pulsating Heat Pipes

2001 ◽  
Author(s):  
M. B. Shafii ◽  
Amir Faghri ◽  
Yuwen Zhang
Keyword(s):  
Heat Transfer ◽  
Finite Difference ◽  
Heat Pipes ◽  
Analytical Models ◽  
Charge Ratio ◽  
Sensible Heat ◽  
Governing Equations ◽  
Heating Wall ◽  
Heat Mode ◽  
Explicit Finite Difference

Abstract Analytical models for both unlooped and looped Pulsating Heat Pipes (PHPs) with multiple liquid slugs and vapor plugs are presented in this study. The governing equations are solved using an explicit finite difference scheme to predict the behavior of vapor plugs and liquid slugs. The results show that the effect of gravity on the performance of top heat mode unlooped PHP is insignificant. The effects of diameter, charge ratio, and heating wall temperature on the performance of looped and unlooped PHPs are also investigated. The results also show that heat transfer in both looped and unlooped PHPs is due mainly to the exchange of sensible heat.

scholarly journals Three Dimensional Transient Explicit Finite Difference Heat Transfer Modeling of Billet Transport

2013 ◽  
Vol 06 (2) ◽  
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Finite Difference ◽  
Coming Out ◽  
Three Dimensional ◽  
Suitable Model ◽  
Billet Temperature ◽  
Reheat Furnace ◽  
Explicit Finite Difference ◽  
Force Calculation

In steel industries the billets are heated in reheat furnace. The billets coming out from reheat furnace are transported to the rolling mill. Prediction of billet temperature during transport is vital for several reasons, like energy optimization studies, process simulation, roll force calculation and quality of the final product. Inadequate temperature measuring instruments demands suitable model for billet temperature predictions. In the present work, conduction heat transfer within the billet is modeled using the explicit finite difference method. To solve three dimensional transient discretization equations, code has been developed and implemented in MATLAB ® . Validation of the proposed numerical model has been done using analytical solutions. The model predictions of billet temperature are shown to be in good concurrence with analytical results. The model is capable of predicting temperature distribution within the billet. The model is used to examine the effect of billet transport velocity on the temperature field of the billet. The objective of this work to apply simple simulation technique to high temperature industrial process for temperature field measurements. This type of simulation may be useful for temperature predictions, design and study of new or existing transport system for hot billet transport.

Lattice Boltzmann Analysis of the Heat Transfer in Cubical Enclosures

2012 ◽  
Vol 326-328 ◽  
pp. 536-541
Author(s):  
Djamel Eddine Ameziani ◽  
Rachid Benacer ◽  
Mohamed Belmedani ◽  
Abdelkader Boutraa
Keyword(s):  
Heat Transfer ◽  
Rayleigh Number ◽  
Finite Difference ◽  
Aspect Ratio ◽  
Finite Difference Method ◽  
Lattice Boltzmann ◽  
Thermal Characteristics ◽  
Governing Equations ◽  
Boltzmann Method

The purpose of this work is to study hydrodynamic and thermal characteristics of air contended into a differentially heated cubic cavity. Due to their importance in the characterization of heat transfer in this kind of configuration, the effect of some parameters is analyzed. It consists in the Rayleigh number and the aspect ratio. In order to resolve the governing equations, the Lattice-Boltzmann method coupled with finite difference method is used.

scholarly journals Explicit Finite Difference Solution of Heat Transfer Problems of Fish Packages in Precooling

2004 ◽  
Vol 1 (2) ◽  
pp. 115-120 ◽  
Author(s):  
A. S. Mokhtar ◽  
K. A. Abbas ◽  
M. M. H. Megat Ahmad ◽  
S. M. Sapuan ◽  
A.O. Ashraf ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Difference ◽  
Finite Difference Solution ◽  
Explicit Finite Difference ◽  
Transfer Problems ◽  
Difference Solution

Analysis of Transient Pressures in Bubbly, Homogeneous, Gas-Liquid Mixtures

1990 ◽  
Vol 112 (2) ◽  
pp. 225-231 ◽  
Author(s):  
M. Hanif Chaudhry ◽  
S. Murty Bhallamudi ◽  
C. Samuel Martin ◽  
M. Naghash
Keyword(s):  
Fluid Flow ◽  
Finite Difference ◽  
Liquid Mixture ◽  
Nonlinear Partial Differential Equations ◽  
Transient State ◽  
Liquid Mixtures ◽  
Finite Difference Schemes ◽  
Piping System ◽  
Governing Equations ◽  
Explicit Finite Difference

Flow of a gas-liquid mixture in a piping system may be treated as a pseudo-fluid flow if the mixture is homogeneous and the void fraction is small. The governing equations for such flows are a set of nonlinear partial differential equations with pressure dependent coefficients. Shocks may be produced during transient state conditions. For numerical integration of these equations, two second-order explicit finite-difference schemes are introduced. To verify validity of the computed results, they are compared with the experimental results.

scholarly journals Analysis of Magnetohydrodynamics Flow of Incompressible Fluids over Oscillating Bottom Surface with Heat and Mass Transfer

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Vincent M. Bulinda ◽  
Giterere P. Kang’ethe ◽  
Phineas R. Kiogora
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Incompressible Fluids ◽  
Bottom Surface ◽  
Two Dimensional ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Explicit Finite Difference ◽  
Explicit Finite Difference Method

Analysis of magnetohydrodynamics flow of incompressible fluids over an oscillating bottom surface with heat and mass transfer is discussed. The flow is free convection in nature. Momentum, energy, and concentration equations are obtained for computation of their respective profiles. The unsteady flow two-dimensional governing equations are solved numerically by the explicit finite difference method of the Forward Time Backward Space scheme. The numerical results show that the applied parameters have significant effects on the fluid flow and heat transfer and have been discussed with the help of graphical illustrations.

An Example of Transient Laminar Countercurrent Flow

1987 ◽  
Vol 109 (3) ◽  
pp. 262-267 ◽  
Author(s):  
I. K. Tsanis ◽  
H. J. Leutheusser
Keyword(s):  
Experimental Study ◽  
Finite Difference ◽  
Pressure Gradient ◽  
Difference Scheme ◽  
Finite Difference Scheme ◽  
Time Dependent ◽  
Countercurrent Flow ◽  
Governing Equations ◽  
Numerical Predictions ◽  
Explicit Finite Difference

This paper presents a numerical and experimental study of transient laminar countercurrent flow in which the pressure gradient is time-dependent. An explicit finite-difference scheme is used to solve numerically the governing equations. Experimental results are obtained with a new kind of apparatus and are found to verify the numerical predictions.

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