Conservatism of the Grid Convergence Index in Finite Volume Computations on Steady-State Fluid Flow and Heat Transfer

2003 ◽  
Vol 125 (4) ◽  
pp. 731-732 ◽  
Author(s):  
Patrick J. Roache
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Finite Volume ◽  
Flow And Heat Transfer ◽  
Grid Convergence ◽  
Grid Convergence Index

Verification of Finite Volume Computations on Steady-State Fluid Flow and Heat Transfer

2001 ◽  
Vol 124 (1) ◽  
pp. 11-21 ◽  
Author(s):  
J. Cadafalch ◽  
C. D. Pe´rez-Segarra ◽  
R. Co`nsul ◽  
A. Oliva
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Finite Volume ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Independent Solution ◽  
Post Processing ◽  
Square Duct ◽  
Flow And Heat Transfer

This work presents a post-processing tool for the verification of steady-state fluid flow and heat transfer finite volume computations. It is based both on the generalized Richardson extrapolation and the Grid Convergence Index GCI. The observed order of accuracy and a error band where the grid independent solution is expected to be contained are estimated. The results corresponding to the following two and three-dimensional steady-state simulations are post-processed: a flow inside a cavity with moving top wall, an axisymmetric turbulent flow through a compressor valve, a premixed methane/air laminar flat flame on a perforated burner, and the heat transfer from an isothermal cylinder enclosed by a square duct. Discussion is carried out about the certainty of the estimators obtained with the post-processing procedure. They have been shown to be useful parameters in order to assess credibility and quality to the reported numerical solutions.

scholarly journals The Influence of Different Types of Nanofluid on Thermal and Fluid Flow Performance of Liquid Cold Plate

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Pressure Drop ◽  
Volume Fraction ◽  
Cold Plate ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Different Types ◽  
Volume Method

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.

scholarly journals Heat Transfer and Thermal Deformation Characteristics of Liquid-Cooled Laser Mirror

2014 ◽  
Vol 6 ◽  
pp. 749065 ◽  
Author(s):  
Panpan Hu ◽  
Haihong Zhu ◽  
Chongwen He ◽  
Xiaoming Ren
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Fluid Flow ◽  
Finite Volume ◽  
Thermal Deformation ◽  
Numerical Models ◽  
Element Model ◽  
Flow And Heat Transfer ◽  
Finite Volume Element ◽  
Transient Thermal

A coupled finite volume-element method is developed to simulate the transient thermal deformation of water-cooled mirror by considering fluid flow and convective heat transfer. The simulation process consists of two steps: the 3D finite volume models of fluid flow and heat transfer equation are solved to obtain the time-dependent temperature field by using CFD; then, the obtained temperature field used as final temperature field is unidirectionally coupled to the finite element model for solving the thermoplastic equation. It is concluded that fluid flow not only affects the magnitude of temperature rise and thermal deformation, but also affects the distribution of temperature and thermal deformation. The temperature gradient in the thickness direction ( z direction) is found to be much larger than that in transverse direction. It is found that the temperature and the consequent deformation of water-cooled mirror increase significantly in the first seconds and gradually become steady state in the subsequent time. Experiments are conducted to estimate the precision of numerical models, and the experimental results agree well with the simulated results.

scholarly journals RANS Simulation of the Effect of Pulse Form on Fluid Flow and Convective Heat Transfer in an Intermittent Round Jet Impingement

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 4025
Author(s):  
M. A. Pakhomov ◽  
V. I. Terekhov
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Steady State ◽  
Jet Impingement ◽  
Pulse Frequency ◽  
Steady State Flow ◽  
Pulsed Jet ◽  
Flow And Heat Transfer ◽  
Pulse Form

The of effect pulse form (rectangular, sinusoidal and triangular) on the fluid flow and heat transfer of an intermittent jet impingement was studied numerically. It was shown in a non-steady-state jet, both an increase and decrease in heat transfer are possible compared with steady-state jet for all investigated pulse forms. For small distances between the pipe edge and obstacle (H/D ≤ 6) in the pulsed jet, heat transfer around the stagnation point increases with increasing pulse frequency, while for H/D > 8 an increase in frequency causes a heat transfer decrease. A growth in the Reynolds number causes a decrease in heat transfer, and data for all frequencies approach the steady-state flow regime. The numerical model is compared with the experimental results. Satisfactory agreement on the influence of the form and frequency of pulses on heat transfer for the pulsed jet on the obstacle surface is obtained.

Steady-State Network Thermofluid Models of Loop Heat Pipes

2007 ◽  
Author(s):  
Nima Atabaki ◽  
Nirmalakanth Jesuthasan ◽  
B. Rabi Baliga
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Phase Region ◽  
Vapor Transport ◽  
Two Phase ◽  
Liquid Transport ◽  
One Dimensional ◽  
Flow And Heat Transfer ◽  
Transport Line

A loop heat pipe (LHP) with one evaporator, a vapor-transport line, a single condenser, a liquid-transport line, and a compensation chamber is considered. The evaporator is an internally grooved circular pipe, with an annular wick installed on its inner surface. The wick is made of sintered powder metal. The condenser is a horizontal tube that is fitted with excellent thermal contact inside a metallic sleeve that is immersed in a constant-temperature bath maintained at a fixed sink temperature. Two different network thermofluid models of this LHP operating under steady-state conditions are presented. In the first (basic) model, quasi one-dimensional mathematical models of the fluid flow and heat transfer in each of the elements of the LHP are used; the pressure drop in the two-phase region of the condenser is ignored; and a relatively simple correlation is used to model the heat transfer in the two-phase region of the condenser. In the second (segmented) model, quasi one-dimensional control volumes or cells are used for the simulation of fluid flow and heat transfer in the vapor-transport line, the condenser, and the liquid-transport line, in order to better account for the variation of fluid properties and the quality (in two-phase regions); and the pressure drops in the two-phase regions are accounted for. The working fluid considered in this investigation is ammonia, but the proposed models can be used with any suitable fluid. Results pertaining to the LHP performance for a range of operating conditions are presented. Some of these results are compared to corresponding results of an earlier experimental investigation in the literature: good agreement is obtained with both models.

scholarly journals Numerical study of Unsteady Fluid Flow and Heat Transfer Through a Rotating Curved Rectangular Channel

2018 ◽  
Vol 37 ◽  
pp. 73-92 ◽  
Author(s):  
Md Zohurul Islam ◽  
Md Arifuzzaman ◽  
Rabindra Nath Mondal
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Unsteady Flow ◽  
Numerical Study ◽  
Rectangular Channel ◽  
Chaotic Flow ◽  
Flow And Heat Transfer ◽  
Unsteady Fluid Flow ◽  
Unsteady Fluid

Numerical study of unsteady fluid flow and heat transfer through a rotating curved rectangular channel with aspect ratio 2 and curvature ratio 0.05 has been performed by using a spectral-based numerical method, and covering a wide range of the rotational parameter, the Taylor number Ta, for both the positive and negative rotation of the channel. In this paper, unsteady flow characteristics are investigated under combined action of the centrifugal, Coriolis and buoyancy forces for the Dean number De = 1000. For positive rotation, we investigated unsteady solutions for 0 ≤Ta ≤500, and it is found that the chaotic flow turns into steady-state flow through periodic or multi-periodic flows. For negative rotation, on the other hand, unsteady solutions are investigated for –500 ≤Ta≤0, and it is found that the unsteady flow undergoes through various flow instabilities. Typical contours of secondary flow patterns and temperature profiles are obtained at several values of Ta, and it is found that the unsteady flow consists of asymmetric two- to eightvortex solutions. The present study shows that convective heat transfer is significantly enhanced as the secondary flow becomes stronger and the chaotic flow enhances heat transfer more effectively than the steady-state or periodic solutions.GANIT J. Bangladesh Math. Soc.Vol. 37 (2017) 73-92

A Parametric Numerical Study of Fluid Flow and Heat Transfer in a Computer Chassis

2015 ◽  
Vol 9 (3) ◽  
pp. 242 ◽  
Author(s):  
Efstathios Kaloudis ◽  
Dimitris Siachos ◽  
Konstantinos Stefanos Nikas
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Flow And Heat Transfer
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