Fluid Flow Resistance in a Simple Cubic Packed Bed

2005 ◽  
Author(s):  
C. C.-C. Choi ◽  
S. H.-K. Lee
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Network Model ◽  
Flow Resistance ◽  
Flow Behavior ◽  
Packed Bed ◽  
Correlation Factor ◽  
Creeping Flow ◽  
Void Space ◽  
Simple Cubic

Motivated by its frequent appearance in practical applications, scientists and engineers have been putting much efforts to pursue the ability to predict fluid flow behavior in sphere packed bed, in particular the fluid-solid interaction therein. The network model has recently been used to predict the fluid flow behavior in a sphere packed bed for a smaller length-scale domain of interest. The major questions for this approach are the representation of the irregular void space as a three dimensional network and the assignment of the flow resistance values. The application of Deluanay Cell to discretize the void space helps retain the geometrical and topological information without any empirical data fitting in. However, the calculation of the flow resistance within the Delaunay cell is still a question to be solved due to its highly irregular topology. The objective of this study is to solve for the flow resistance between the pores in a simple cubic retaining all the geometrical information. And then to correlate the flow resistance with different values of Reynolds number such that the application of network model could extend outside the creeping flow regime. The results has been validated against experimental correlation and then correlated with Reynolds number with a correlation factor larger than 0.9.

scholarly journals Convection Heat Transfer Analysis with Flow Resistance for Mini-Helically Coiled Tubes at Supercritical Pressures Experimentally

2021 ◽  
Vol 39 (3) ◽  
pp. 817-824
Author(s):  
Ameer Abed Jaddoa
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Mass Flux ◽  
Flow Resistance ◽  
Convection Heat Transfer ◽  
Heat Fluxes ◽  
Exergy Destruction ◽  
Convection Heat

This paper analyzes the effect of fluid flow characteristics on the convection heat transfer for mini-helically coiled tubes (HCT) using supercritical carbon dioxide (CO2) as a natural refrigerant. Two experimental cases have studied in this work for mini-helically coiled tubes at different diameters with different coil pitches for analyzing the convection heat transfer with flow resistance. In the first case, the inner tube diameter, coil diameter and coil pitch were 5 mm, 200 mm and 10 mm respectively, while 10 mm, 100 mm and 5 mm were for the second case. Moreover, this work has also investigated the influence of frictional pressure drop, heat flux, friction factor and mass flux on dimensionless exergy destruction. The work environments were 300-500 K as an inlet temperatures range, 200-2000 Kg / (m2. s) as a mass heat fluxes range, 50,000-500,000 as a Reynolds number (Re) range and 50-200 Kw/m2 as an inner heat fluxes range. As a result, a large effect has been observed for dimensionless exergy destruction compared with the flow friction of CO2 which induced by heat transfer irreversibility. On the other point of view, a good sensitivity of optimal Re with the tube dimeter and mass flux also noticed compared with the heat flux. At a suitable range for Re, smallest and best exergy destruction also noticed for the tube diameters. A correlation has for the optimal Reynolds number as function of main dimensionless parameters related to wall heat flux, mass flux, fluid properties and geometric dimensions is proposed. Characteristics of the fluid flow had influenced significantly by mass and heat fluxes. In the future, the collected experimental data can be employed in order to design and improve the refrigeration conditioning performance for exchangers and other systems such as heat pumps.

Accurate Numerical Prediction of Incompressible Fluid Flow in Lid-Driven Cavities

2011 ◽  
Vol 110-116 ◽  
pp. 4365-4372
Author(s):  
Abdul Munir Fudhail ◽  
Mohd Rody Mohamad Zin ◽  
Nor C. Sidik Azwadi ◽  
Mohd Azli Salim
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Aspect Ratio ◽  
Incompressible Fluid ◽  
Numerical Method ◽  
Stream Function ◽  
Numerical Experiments ◽  
Flow Behavior ◽  
Incompressible Fluid Flow ◽  
Primary Vortex

In this paper, we report an efficient numerical method to predict fluid flow behavior in a square and deep lid-driven cavities. The conventional continuity and momentum equations are transformed into stream-function and vorticity formulation to reduce the number of unknown spatial quantities. Numerical experiments were performed with different values of aspect ratio and Reynolds number to investigate the effect of these dimensionless parameters on the fluid flow behavior in the cavity. In the current study, we found that the dynamics and the structure of primary vortex are significantly affected by the Reynolds number and the aspect ratio of the cavity.

scholarly journals Methodology of heat transfer and flow resistance measurement for matrices of rotating regenerative heat exchangers

2016 ◽  
Vol 37 (3) ◽  
pp. 341-358 ◽  
Author(s):  
Dariusz Butrymowicz ◽  
Jarosław Karwacki ◽  
Roman Kwidziński ◽  
Kamil Śmierciew ◽  
Jerzy Gagan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Resistance ◽  
Packed Bed ◽  
Indirect Measurement ◽  
Measured Temperature ◽  
Auxiliary Equipment ◽  
Regenerative Heat ◽  
Wide Range ◽  
Measurement Approach

Abstract The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.

Effects of Roughness on Liquid Flow Behavior in Ducts

2006 ◽  
Author(s):  
Jiang Zou ◽  
Xiao-Feng Peng
Keyword(s):  
Reynolds Number ◽  
Flow Resistance ◽  
Flow Model ◽  
Flow Behavior ◽  
Reattachment Length ◽  
Roughness Effects ◽  
Relative Roughness ◽  
Roughness Elements ◽  
Modified Formula ◽  
Flow Cross

In this paper, liquid laminar flow friction in micro/mini ducts is considered for investigating the effects of roughness. The available research in this field is briefly reviewed, and the results are comprehensively discussed. The flow behavior is theoretically analyzed in the region adjacent to rough wall, and one of roughness effects is considered equivalent to the reduction of flow cross area, which is referred to the constricted flow model. A modified formula and coefficient η are introduced to correct the reduction value of hydraulic diameter. Two important factors, the space of two neighboring roughness elements and the reattachment length, are involved in accounting for the flow cross-section reduction. Eventually, an expression of flow resistance calculation is reduced in terms of relative roughness ε/d, parameter A and Reynolds number Re. Based on the ultimate friction factor formula, the influences of relative roughness ε/d, parameter A and Reynolds number Re on friction coefficient f are discussed by figuring and comparing f variation with those parameters.

Fluid Flow Behavior for a Confined Rotating MCM Disk With Round Jet Array Impingement

2007 ◽  
Author(s):  
C. J. Fang ◽  
C. Y. Lee ◽  
C. H. Peng ◽  
T. W. Lin ◽  
Y. H. Hung
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Turbulence Intensity ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Jet Impingement ◽  
Streamwise Velocity ◽  
Potential Core ◽  
Round Jet ◽  
Jet Array

A series of experimental investigations on the studies related to fluid flow characteristics of a confined rotating Multi-Chip Module (MCM) disk with round air jet array impingement have been performed. The relevant parameters influencing fluid flow characteristics include the ratio of jet separation distance to nozzle diameter (H/d), jet Reynolds number (Rej) and rotational Reynolds number (Rer). The parametric ranges are Rej = 712 – 4087, Rer = 0 – 2906, H/d = 0.83–14.4 and Z/d = 1–7. The potential core lengths of all the nozzle jets increases with increasing jet Reynolds number or H/d ratio and decreases with increasing rotational Reynolds number. New correlations of the ratio of potential core length to nozzle diameter at various nozzle jets in terms of relevant influencing parameters are proposed. Furthermore, the strengths on both streamwise velocity and turbulence intensity increase with increasing Z/d ratio. The turbulence intensity for the cases of jet array impingement growing up along the axial directions are significantly faster than the cases of single round jet impingement. The jet array impingement has a higher momentum flux in the flow interaction region between two adjacent nozzles; accordingly, it can achieve a more uniform thermal performance as compared with the cases of single round jet impingement. Near-surface fluid flow behavior including the streamwise velocity and turbulence intensity distributions can be employed to interpret the heat transfer characteristics for jet array impingement.

Fluid Flow Resistance Through Hemispherical Dimpled Plates in Parallel and Zigzag Configurations

2018 ◽  
Vol 12 (11) ◽  
pp. 885
Author(s):  
Nasaruddin Salam ◽  
Rustan Tarakka ◽  
Jalaluddin Jalaluddin ◽  
Muh. Setiawan Sukardin
Keyword(s):  
Fluid Flow ◽  
Flow Resistance
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