scholarly journals An empirical correlation for isothermal parallel plate channel completely filled with porous media

2013 ◽  
Vol 17 (4) ◽  
pp. 1061-1070 ◽  
Author(s):  
Mohammad Hamdan
Keyword(s):  
Porous Media ◽  
Nusselt Number ◽  
Steady State ◽  
Friction Factor ◽  
Parallel Plate ◽  
Empirical Correlation ◽  
Empirical Correlations ◽  
Fully Developed Flow ◽  
Forchheimer Model ◽  
Plate Channel

This study reports a simple empirical correlation for friction factor and Nusselt number for laminar, steady state, hydraulically and thermally fully developed flow in isothermal parallel plate channel completely filled with porous media. The study is carried out using a finite difference numerical analysis. The Darcy-Brinkman-Forchheimer model is used to model the flow inside the porous media. The empirical correlations are developed to relate friction factor and Nusselt number to Darcy and Forchheimer coefficient.

Nonlinear Study of Convective Heat Transfer in Tightly Curved Rectangular Microchannels

2016 ◽  
Author(s):  
Fang Liu
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Steady State ◽  
Friction Factor ◽  
Flow Instability ◽  
Numerical Study ◽  
Chaotic Oscillation ◽  
Periodic Oscillation ◽  
Stable Steady State ◽  
Rectangular Microchannels

To address the effects of curvature, initial conditions and disturbances, a numerical study is made on the fully-developed bifurcation structure and stability of the forced convection in tightly curved rectangular microchannels of aspect ratio 10 and curvature ratio 0.5 at Prandtl number 7.0. Eleven solution branches (seven symmetric and four asymmetric) are found with 10 bifurcation points and 27 limit points. The flows on these branches are with 2, 4, 6, 7, 8, 9 or 10-cell structures. The flow structures change along the branch because of the flow instability. The average friction factor and Nusselt Number are different on different solution branches. It is found that more than 22.33% increase in Nu can be achieved with less than 9.34% increase in fRe at Dk of 2000. As Dean number increases, finite random disturbances lead the flows from a stable steady state to another stable steady state, a periodic oscillation, an intermittent oscillation, another periodic oscillation and a chaotic oscillation. The mean friction factor and mean Nusselt Number are obtained for all physically realizable flows. A significant enhancement of heat transfer can be obtained at the expense of a slightly increase of flow friction in tightly coiled rectangular ducts.

Analytical Solution for Newtonian Laminar Flow Through the Concave and Convex Ducts

2009 ◽  
Vol 131 (9) ◽  
Author(s):  
M. Firouzi ◽  
S. H. Hashemabadi
Keyword(s):  
Reynolds Number ◽  
Steady State ◽  
Friction Factor ◽  
Cross Section ◽  
Cross Sections ◽  
Fully Developed Flow ◽  
Pipe Flows ◽  
Dimensionless Velocity ◽  
Flow Through ◽  
Fanning Friction Factor

In this paper, the motion equation for steady state, laminar, fully developed flow of Newtonian fluid through the concave and convex ducts has been solved both numerically and analytically. These cross sections can be formed due to the sedimentation of heavy components such as sand, wax, debris, and corrosion products in pipe flows. The influence of duct cross section on dimensionless velocity profile, dimensionless pressure drop, and friction factor has been reported. Finally based on the analytical solutions three new correlations have been proposed for the product of Reynolds number and Fanning friction factor (Cf Re) for these geometries.

Aggregate Intensification of Natural Convection Between Air and a Vertical Parallel-Plate Channel by Inserting an Auxiliary Plate at the Mouth and Appending Colinear Insulated Plates at the Exit

2000 ◽  
Author(s):  
Assunta Andreozzi ◽  
Oronzio Manca ◽  
Antonio Campo
Keyword(s):  
Nusselt Number ◽  
Parallel Plate ◽  
Navier Stokes ◽  
Working Fluid ◽  
Uniform Heat Flux ◽  
Heated Plate ◽  
Computational Domain ◽  
Plate Height ◽  
Pressure Profiles ◽  
Plate Channel

Abstract This paper addresses the examination of heat transfer in parallel-plate channels using a combination of two passive schemes: (1) the insertion of an auxiliary plate at the mouth and (2) the appendage of colinear insulated plates at the exit. The investigation is made by numerically solving the full elliptic Navier-Stokes and energy equation in a I-type computational domain. The channel is symmetrically heated by uniform heat flux. The working fluid is air. The results are reported in terms of induced mass flow rate and maximum wall temperatures. Further, the local Nusselt number, the mean Nusselt number and pressure profiles are presented. The analyzed Grashof numbers based on the heated plate height are 103 and 106.

scholarly journals An improved algebraic model for by-pass transition for calculation of transitional flow in pipe and parallel-plate channels

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1123-1131
Author(s):  
Konrad Nering ◽  
Kazimierz Rup
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Turbulence Intensity ◽  
Parallel Plate ◽  
Algebraic Model ◽  
Transitional Flow ◽  
Internal Flows ◽  
Fully Developed Flow ◽  
Turbulent Transition ◽  
Plate Channel

Modified algebraic intermittency model developed by E. Dick and S. Kubacki was used to describe laminar-turbulent transition. In this work a modification of this model was made for simulating internal flows in pipes and parallel-plate channel. In particular, constants present in this model were modified. These modified constants are the same for different flows in pipes and parallel-plate channels. In this work, a dependence of friction factor on Reynolds number and turbulence intensity were determined as well as the localization of laminar breakdown and fully developed flow. Obtained results were compared with theoretical and experimental data presented in the literature.

Prediction of Forced Convection Flow in a Parallel Plate Channel Filled With Porous Media

2009 ◽  
Author(s):  
Dana Ehyaei ◽  
Hamed Honari ◽  
M. Rahimian
Keyword(s):  
Porous Media ◽  
Nusselt Number ◽  
Flow Field ◽  
Convection Flow ◽  
Parallel Plates ◽  
Two Dimensional Flow ◽  
Porous Domain ◽  
Forced Convection Flow ◽  
Plate Channel ◽  
Transfer Properties

In this study the flow field and heat transfer properties of a steady, two-dimensional flow field in a porous domain between two parallel plates is investigated numerically by using a discretized numeric code. Analysis has been carried for Reynolds number based on particle sizes ranging from 60 to 1000. Numerical results are compared with different numerical methods used for predicting this kind of flow. Results are obtained for different regime, various Rep numbers and the effect of Particles size is also investigated. Solutions indicate that by increasing the Rep, the flow in the porous media remains laminar where the flow has turbulence characteristics for Rep <50. Moreover, by increasing Rep, the value of average Nusselt number increases. Also, reducing the particle size affects the Nusselt number and it increases while the porosity remains the same.

Heat Transfer to Laminar Flow in Tapered Passages

1965 ◽  
Vol 32 (3) ◽  
pp. 684-689 ◽  
Author(s):  
E. M. Sparrow ◽  
J. B. Starr
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Wall Temperature ◽  
Parallel Plate ◽  
Laminar Flows ◽  
Wall Heat Flux ◽  
Heat Transfer Analysis ◽  
Plate Channel

Consideration is given to the fully developed heat-transfer characteristics of laminar flows in converging and diverging plane-walled passages. The analysis is carried out for the two fundamental thermal boundary conditions of prescribed wall heat flux and prescribed wall temperature. As a prelude to the heat-transfer analysis, a new solution for the velocity distribution is derived on the basis of a linearized momentum equation. The Nusselt number for flow in tapered passages is found to depend on the Reynolds number; this is in contrast to the situation for passages of longitudinally unchanging cross section wherein the Nusselt number is independent of the Reynolds number. In general, the Nusselt number for flow in a plane-walled diverging passage falls below that for the parallel-plate channel, while the Nusselt number for a converging flow is usually higher than that for a parallel-plate channel. Moreover, the fully developed Nusselt numbers for prescribed wall heat flux exceed those for prescribed wall temperature.

scholarly journals Heat transfer convection of a power law fluid flow within a parallel plate channel provided with two generating obstacles

2018 ◽  
Vol 19 (2) ◽  
pp. 210 ◽  
Author(s):  
Ahlem Boudiaf ◽  
Fetta Danane ◽  
Youb Khaled Benkahla ◽  
Nabila Labsi ◽  
Abdelkader Boutra
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Fluid Flow ◽  
Parallel Plate ◽  
Heat Removal ◽  
Separation Distance ◽  
Simpler Algorithm ◽  
Recirculation Zones ◽  
Volume Method ◽  
Plate Channel

The main objective of this work is to examine the heat transfer changes induced by the presence of heat generating obstacles and that for non-Newtonian fluid flow within a parallel plate channel. The effects of the two obstacle height and the distance between them, on the flow structure and Nusselt number are examined. The Finite Volume Method is used to discretize the conservation equations of mass, momentum, and energy. The SIMPLER algorithm is applied to remove the checkerboard pressure problem. The results are discussed in terms of streamlines and the Nusselt number for three combinations of height and separation distance of the two obstacles. Two recirculation zones are observed for all the cases with different intensity varying with the size of the obstacle and the separation distance. Likewise the results show that the heat removal, occurring by the Nusselt number variations, is widely affected by the size of the obstacles as well as by the distance between them.

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