Numerical Prediction of Flow and Heat Transfer in a Parallel Plate Channel With Staggered Fins

1987 ◽  
Vol 109 (1) ◽  
pp. 25-30 ◽  
Author(s):  
K. M. Kelkar ◽  
S. V. Patankar
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Periodic Variation ◽  
Local Heat ◽  
Temperature Fields ◽  
Parallel Plates ◽  
Constant Property ◽  
Cross Sectional ◽  
Flow And Heat Transfer ◽  
Order Of Magnitude

Fluid flow and heat transfer in two-dimensional finned passages were analyzed for constant property laminar flow. The passage is formed by two parallel plates to which fins are attached in a staggered fashion. Both the plates are maintained at a constant temperature. Streamwise periodic variation of the cross-sectional area causes the flow and temperature fields to repeat periodically after a certain developing length. Computations were performed for different values of the Reynolds number, the Prandtl number, geometric parameters, and the fin-conductance parameter. The fins were found to cause the flow to deflect significantly and impinge upon the opposite wall so as to increase the heat transfer significantly. However, the associated increase in pressure drop was an order of magnitude higher than the increase in heat transfer. Streamline patterns and local heat transfer results are presented in addition to the overall results.

Study on fluid flow and heat transfer in fluid channel filled with KKL model-based nanofluid during natural convection using FVM

2019 ◽  
Vol 29 (8) ◽  
pp. 2622-2641
Author(s):  
Yongsheng Rao ◽  
Zehui Shao ◽  
Alireza Rahimi ◽  
Abbas Kasaeipoor ◽  
Emad Hasani Malekshah
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Entropy Generation ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Temperature Fields ◽  
Bejan Number ◽  
Content Type ◽  
Flow And Heat Transfer

PurposeA comprehensive study on the fluid flow and heat transfer in a nanofluid channel is carried out. The configuration of the channel is as like as quarter channel. The channel is filled with CuO–water nanofluid.Design/methodology/approachThe Koo–Kleinstreuer–Li model is used to estimate the dynamic viscosity and consider the Brownian motion. On the other hand, the influence of nanoparticles’ shapes on the heat transfer rate is considered in the simulations. The channel is included with the injection pipes which are modeled as active bodies with constant temperature in the 2D simulations.FindingsThe Rayleigh number, nanoparticle concentration and the thermal arrangements of internal pipes are the governing parameters. The hydrothermal aspects of natural convection are investigation using different approaches such as average Nusselt number, total entropy generation, Bejan number, streamlines, temperature fields, local heat transfer irreversibility, local fluid friction irreversibility and heatlines.Originality/valueThe originality of this work is investigation of fluid flow, heat transfer, entropy generation and heatline visualization within a nanofluid-filled channel using a finite volume method.

The Effect of Regulating Elements on Convective Heat Transfer along Shaped Heat Exchange Surfaces

2013 ◽  
Vol 34 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Jozef Cernecky ◽  
Jan Koniar ◽  
Zuzana Brodnianska
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Cfd Simulation ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Temperature Fields ◽  
Transfer Coefficients ◽  
Heat Transfer Intensification ◽  
Heat Transfer Coefficients ◽  
Forced Air

Abstract The paper deals with a study of the effect of regulating elements on local values of heat transfer coefficients along shaped heat exchange surfaces with forced air convection. The use of combined methods of heat transfer intensification, i.e. a combination of regulating elements with appropriately shaped heat exchange areas seems to be highly effective. The study focused on the analysis of local values of heat transfer coefficients in indicated cuts, in distances expressed as a ratio x/s for 0; 0.33; 0.66 and 1. As can be seen from our findings, in given conditions the regulating elements can increase the values of local heat transfer coefficients along shaped heat exchange surfaces. An optical method of holographic interferometry was used for the experimental research into temperature fields in the vicinity of heat exchange surfaces. The obtained values correspond very well with those of local heat transfer coefficients αx, recorded in a CFD simulation.

Estimation of Average and Local Heat Transfer in Parallel Plates and Circular Ducts Filled With Porous Materials

2004 ◽  
Vol 126 (3) ◽  
pp. 400-409 ◽  
Author(s):  
A. Haji-Sheikh
Keyword(s):  
Heat Transfer ◽  
Porous Materials ◽  
Practical Interest ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Sufficient Accuracy ◽  
Accurate Estimation ◽  
Parallel Plates ◽  
Transfer Coefficients ◽  
Average Heat

Accurate estimation of heat transfer to a fluid passing through a porous medium located between impermeable walls is of practical interest. Generally, the numerical computation of heat transfer to porous media can become time consuming and correlations are needed to enable practitioners to determine this quantity rapidly. In this paper, correlations for two cases are considered: one when porous materials are between two parallel plates and the other when they are within a circular pipe. This presentation includes correlations for both local and average heat transfer coefficients in these two passages for incompressible laminar flow. These correlations require knowledge of local and average heat transfer for unobstructed fluid flowing through these passages with sufficient accuracy. Because existing correlations lack sufficient accuracy, this presentation includes an appendix that emphasizes correlations for heat transfer to fluids passing through unobstructed parallel plate channels and also for circular pipes.

Numerical Prediction of Flow and Heat Transfer Past a Circular Tube With Annular Fins

2003 ◽  
Author(s):  
D. Chakraborty ◽  
G. Biswas ◽  
P. K. Panigrahi
Keyword(s):  
Heat Transfer ◽  
Circular Tube ◽  
Flow Characteristics ◽  
Cross Flow ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Stagnation Line ◽  
Flow And Heat Transfer ◽  
Annular Fin ◽  
Annular Fins

A numerical investigation was carried out to study the flow and heat transfer behavior of a vertical circular tube, which is situated between two annular fins in cross-flow. The flow structure of the limiting streamlines on the surface of the circular tube and the annular fins was analysed. A finite volume method was employed to solve the Navier-Stokes and energy equations. The numerical results pertaining to heat transfer and flow characteristics were compared with the available experimental results. The following salient features were observed in this configuration. A horseshoe vortex system was formed at the junction of the stagnation line of the circular tube and the annular fin. The separation took place at the rear of the tube. The influence of the horseshoe vortices on local heat transfer was substantial. The ratio of the axial gap between two annular fins (L) to the radial protrusion length of the annular fin (LR) was identified as an important parameter. The flow and heat transfer results were presented for different L/LR ratios for a Reynolds number of 1000.

Flow and Heat Transfer Past a Sudden Contraction With a Porous Insert Using Linear and Non-Linear Turbulence Models

2004 ◽  
Author(s):  
Marcelo Assato ◽  
Marcelo J. S. de Lemos
Keyword(s):  
Heat Transfer ◽  
Turbulence Models ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Porous Insert ◽  
Macroscopic Models ◽  
Flow And Heat Transfer ◽  
Non Linear ◽  
Abrupt Contraction ◽  
Stream Lines

This work presents a numerical investigation for the turbulent flow and heat transfer in an abrupt contraction channel with a porous material placed in a flow passage. The channel has a contraction rate of 3:2. Results for the hybrid medium were obtained using linear and non-linear k-ε macroscopic models. It was used an inlet Reynolds number of Re = 132000 based on the height of the step. Parameters such as porosity, permeability and thickness of the porous insert were varied in order to analyze their effects on the flow pattern. The results of local heat transfer, friction coefficient and stream lines obtained by the two turbulence models were compared for the cases without and with porous insertion of thickness a/H=0.083, 0.166 and 0.250, where H is the step height. Insert porosity of varied between 0.85 and 0.95 with permeability in the range 10−6–10−2 m2.

Simulation of Flow and Heat Transfer in the MTPV Systems

2013 ◽  
Vol 448-453 ◽  
pp. 3291-3295
Author(s):  
Ge Ping Wu ◽  
Jun Wang ◽  
Ping Lu
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Friction Factor ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Transfer Characteristics ◽  
Pressure Losses ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Different Types

Flow and heat transfer characteristics in the microchannel cooling passages with three different types of the MTPV systems are numerically investigated. Reynolds ranged from 100 to 1000 and hydraulic diameter from 0.4mm to 0.8mm. The steady, laminar flow and heat transfer equations are solved in a finite-volume method. The local heat transfer characteristics, thermal resistance, Nusselt numbers, friction factor and pressure losses of the different types are analyzed. A comparison of the heat transfer coefficient, pressure losses and friction factor of the different microchannels are also presented. The heat transfer performance of the rob bundles microchannel is found to be much better than others. However, the rectangular passage has the lowest thermal resistance than the other types of microchannels.

The Effect of Entrance Configuration on Local Heat-transfer Coefficients in Subsonic Diffusers

1972 ◽  
Vol 94 (4) ◽  
pp. 355-359 ◽  
Author(s):  
E. O. Stoffel ◽  
J. R. Welty
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Two Dimensional ◽  
Transfer Coefficients ◽  
Transfer Rates ◽  
Heat Transfer Coefficients ◽  
Flow And Heat Transfer ◽  
Transfer Equations ◽  
Subsonic Diffuser

The effects of square and reentrant entrances on flow regimes (no “appreciable” separation, large transitory stall, and fully developed two-dimensional stall) and local heat-transfer coefficients were determined with air flowing through a symmetrical, plane-wall, two-dimensional subsonic diffuser with one of the diverging walls heated and maintained isothermal. Flow and heat-transfer studies were made for the following ranges: 2θ = 0 to 45 deg, L/W = 6 to 18, and Rextut = 4 × 104 to 3 × 105. Results indicated that 2θ, L/W, and entrance configuration greatly affected the flow regime and heat transfer. Equations relating Um′ to Ut, Ur to Ut, and equations of the type Nu = C Pr0.6Rex0.8 are presented. For the configurations tested, heat-transfer rates were greater for reentrant than for square entrances.

scholarly journals HEAT EXCHANGE IN FOAM CONCRETE REINFORCED BY POLYETHYLENE TEREPHTHALATE FIBER (PET FIBER)

2019 ◽  
Vol 4 (7) ◽  
pp. 121-127
Author(s):  
К. Домнина ◽  
Kseniya Domnina ◽  
Elena Pivarčiová ◽  
Elena Pivarčiová ◽  
В. Репко ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Temperature Fields ◽  
State Technical ◽  
Foam Concrete ◽  
Pet Fibers ◽  
Technical University ◽  
The Heat Transfer Coefficient ◽  
Made In

The article analyzes temperature fields over foam concrete samples reinforced by PET fibers. The samples are developed at the Votkinsk branch of Kalashnikov Izhevsk State Technical University. The effectiveness of reinforced PET fibers has already been proven, but so far, the effect of PET reinforcement on the thermophysical properties of foam concrete has not been well studied. In the laboratories of the Technical University in Zvolen, Slovakia (TUZVO), the heat transfer is analyzed using natural convection by heating reinforced foam concrete samples. The method of holographic interferometry is used, which allows to visualize temperature fields in real time. Temperature fields arising above the samples are displayed and recorded by a Mach-Zehnder interferometer using the «living boundary» method throughout the entire length of the interference fringes. A method for calculating the parameters of heat transfer by analogy with the heating of a flat plate has been proposed. Qualitative and quantitative analyzes of holographic interferograms of the temperature fields are carried out. The local heat transfer parameters are calculated: the heat transfer coefficient α and the heat conductivity coefficient λ. It has been established that the samples of foam concrete reinforced by PET fibers made in Russia have a higher heat resistance and better insulation than foreign analogues.

scholarly journals Laser interferometry - Report #HT-01-2017

2021 ◽  
Author(s):  
David Naylor
Keyword(s):  
Heat Transfer ◽  
Light Beam ◽  
Three Dimensional ◽  
Local Heat Transfer ◽  
Laser Interferometry ◽  
Local Heat ◽  
Temperature Fields ◽  
Fluid Temperature ◽  
Two Dimensional ◽  
Transfer Rates

An introduction is given to the optical setup and principle of operation of classical and holographic interferometers that are used for convective he at transfer measurements. The equations for the evaluation of the temperature field are derived and methods of analysis are discussed for both two-dimensional and three-dimensional temperature fields. Emphasis is given to techniques for measuring local heat transfer rates. For two-dimensional fields, a method is presented for measuring the surface temperature gradient directly from a finite (wedge) fringe interferogram. This “direct gradient method” is shown to be most useful for the measurement of low convective heat transfer rates. For three-dimensional fields, the equations for calculating the beam-averaged local heat flux are presented. The measurement of the fluid temperature averaged along the light beam is shown to be approximate. However, an analysis is presented showing that for most cases the error associated with temperature variations in the light beam direction is small. Digital image analysis of interferograms to obtain fringe spacings is also discussed briefly.

Numerical Investigation on Conjugate Heat Transfer of Supercritical CO2 in Rolling Motion

2018 ◽  
Author(s):  
Zhenxing Zhao ◽  
Mengran Liao ◽  
Yong Liu ◽  
Qi Xiao ◽  
Xingsheng Lao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Supercritical Co2 ◽  
Local Heat Transfer ◽  
Periodic Oscillation ◽  
Local Heat ◽  
Rolling Motion ◽  
Flow And Heat Transfer ◽  
Ocean Environment ◽  
The Stability ◽  
Phase Fluid

The numerical calculations with and without rolling motions were conducted to investigate the effects of ocean environment on flow and heat transfer of supercritical CO2. The AKN k-epsilon model was selected to model the turbulent flow and heat transfer of supercritical fluid. It concludes that the effect of rolling motion on the supercritical CO2 in LPV region is much greater than that on conventional single-phase fluid. The rolling motion can cause the periodic oscillation of the local heat transfer and suppress the nonuniform heat transfer. The secondary flow is induced by both the rolling motion and buoyancy force. The heat transfer is enhanced gradually as the rolling period decreasing or rolling amplitude increasing, but the corresponding pressure drop varies more violently to affect the stability and controllability of the heat exchanger.

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