Three-Dimensional Fluid Flow and Coupled Heat Transfer in Simplified Bipolar Plates

2007 ◽  
Author(s):  
Jianfei Wu ◽  
Jianhu Nie ◽  
Yitung Chen
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Solid Wall ◽  
Three Dimensional ◽  
Cathode Side ◽  
Uniform Heat Flux ◽  
Bipolar Plates ◽  
Coupled Heat Transfer ◽  
Temperature Distributions

Numerical simulations were performed for three-dimensional fluid flow and coupled heat transfer in simplified bipolar plates. The Reynolds number of inlet flow is varied from 100 to 900 on the anode side while the Reynolds number is maintained as a constant of 100 on the cathode side. The solid wall surfaces of the bipolar plates are assumed to be adiabatically insulated, except that the active areas of the channels are supplied with uniform heat flux. Results of velocity and temperature distributions for different Reynolds numbers are presented and discussed. It is shown that effects of flow pattern on temperature distributions in channels becomes negligible when the Reynolds number is as high as 900.

scholarly journals Numerical Simulations of Three-Dimensional Fluid Flow and Coupled Heat Transfer in Bipolar Plates

2007 ◽  
Author(s):  
Jianfei Wu ◽  
Jianhu Nie ◽  
Yitung Chen
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Electrolysis Cell ◽  
Bipolar Plates ◽  
Coupled Heat Transfer ◽  
High Efficient ◽  
Pem Electrolysis

Bipolar plate is one of the key components in PEM electrolysis cell stacks, and it performs a number of essential functions in stack operation, such as reactant supply to the cell active area, current collection, and mechanical support to the MEA. High efficient PEM electrolysis cell stacks will require optimized bipolar plates. Improvements in the design of bipolar plates can help achieve the set goals of cost and performance for the PEM electrolysis cell. In the present work, numerical simulations were performed for three-dimensional fluid flow and coupled heat transfer in bipolar plates. The Reynolds number of inlet flow is varied from 100 to 900 on the anode side while the Reynolds number is maintained as a constant of 100. The solid wall surfaces of the bipolar plates are assumed to be adiabatically insulated, except that the active areas of the channels are supplied with uniform heat flux. Results of velocity and temperature distributions for different Reynolds numbers will be presented and discussed.

Numerical and Experimental Prediction of Transitional Characteristics of Flow and Heat Transfer in an Array of Heated Blocks

1999 ◽  
Vol 121 (3) ◽  
pp. 202-208 ◽  
Author(s):  
Y. Asako ◽  
Y. Yamaguchi ◽  
M. Faghri
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Parallel Plate ◽  
Three Dimensional ◽  
Parallel Plates ◽  
Number Range ◽  
Flow And Heat Transfer ◽  
Numerical Predictions ◽  
Experimental Prediction

Three-dimensional numerical analysis, for transitional characteristics of fluid flow and heat transfer in periodic fully developed region of an array of the heated square blocks deployed along one wall of the parallel plates duct, is carried out by using Lam-Bremhorst low-Reynolds-number two equation turbulence model. Computations were performed for Prandtl number of 0.7, in the Reynolds number range of 200 to 2000 and for two sets of geometric parameters characterizing the array. The predicted transitional Reynolds number is lower than the value for the parallel plate duct and it decreases with increasing the height above the module. Experiments were also performed for pressure drop measurements and for flow visualization and the results were compared with the numerical predictions.

A Numerical Study of Flow and Heat Transfer in a Smooth and Ribbed U-Duct With and Without Rotation

2000 ◽  
Vol 123 (2) ◽  
pp. 219-232 ◽  
Author(s):  
Y.-L. Lin ◽  
T. I.-P. Shih ◽  
M. A. Stephens ◽  
M. K. Chyu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Mach Number ◽  
Vector Fields ◽  
Numerical Study ◽  
Density Ratio ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Flow And Heat Transfer

Computations were performed to study the three-dimensional flow and heat transfer in a U-shaped duct of square cross section under rotating and non-rotating conditions. The parameters investigated were two rotation numbers (0, 0.24) and smooth versus ribbed walls at a Reynolds number of 25,000, a density ratio of 0.13, and an inlet Mach number of 0.05. Results are presented for streamlines, velocity vector fields, and contours of Mach number, pressure, temperature, and Nusselt numbers. These results show how fluid flow in a U-duct evolves from a unidirectional one to one with convoluted secondary flows because of Coriolis force, centrifugal buoyancy, staggered inclined ribs, and a 180 deg bend. These results also show how the nature of the fluid flow affects surface heat transfer. The computations are based on the ensemble-averaged conservation equations of mass, momentum (compressible Navier-Stokes), and energy closed by the low Reynolds number SST turbulence model. Solutions were generated by a cell-centered finite-volume method that uses second-order flux-difference splitting and a diagonalized alternating-direction implicit scheme with local time stepping and V-cycle multigrid.

Effect of Finite Width on Heat Transfer and Fluid Flow about an Inclined Rectangular Plate

1979 ◽  
Vol 101 (2) ◽  
pp. 199-204 ◽  
Author(s):  
E. M. Sparrow ◽  
J. W. Ramsey ◽  
E. A. Mass
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Transfer Coefficient ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Normal Incidence ◽  
Finite Width ◽  
Number Range ◽  
Narrow Plate

Wind tunnel experiments were performed to study the heat transfer and fluid flow characteristics for finite-width rectangular plates inclined at various angles of attack to an oncoming airflow. Plates having ratios of spanwise width to streamwise length of 0.4 and 2.5 were employed, and the angle of attack was varied from 90 deg (normal incidence) to 25 deg. The Reynolds number range extended from about 20,000 to 90,000. The naphthalene sublimation technique was used in the transfer coefficient determinations, and the fluid flow patterns adjacent to the plate were made visible by the oil/lampblack technique. The flow field was found to be highly complex and three dimensional, with stronger three-dimensional effects in evidence for the narrow plate. A stagnation zone, centered in the plate cross section at normal incidence, moved forward and ultimately disappeared as the plate was inclined at smaller angles of attack. The dimensionless heat (mass) transfer coefficient, expressed in terms of the Colburn j-factor, varied as the square root of the Reynolds number for all angles of attack, both for the narrow and the wider plates. For the wider plate, the transfer coefficients are completely independent of the angle of attack in the range investigated, while for the narrow plate there is an overall variation of twenty percent. An algebraically simple correlation of all the results, accurate to ± 10 percent, is given to facilitate their use in applications such as the wind-related heat loss from flat plate solar collectors.

Effect of Aspect Ratio on Overall Thermal Performance of Forced Convective Heat Transfer Utilizing Turbulent Nanofluid Flow

2020 ◽  
pp. 1-22
Author(s):  
Hani Hinnawi ◽  
Abdulnaser Al-abadi ◽  
Naser S. Al-Huniti
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Aspect Ratio ◽  
Three Dimensional ◽  
Uniform Heat Flux ◽  
Nanofluid Flow ◽  
Maximum Enhancement ◽  
Channel Aspect Ratio ◽  
Flow Through ◽  
Volume Method

Abstract This work is concerned with studying the performance of SiO2–water nanofluid flow through a three-dimensional straight mini-channel with different values of aspect ratio (AR) of (0.5, 1.0, and 1.6) and a fixed hydraulic diameter under a uniform heat flux. The governing equations are developed and solved numerically using the finite volume method for a single-phase flow with standard Kappa-epsilon (κ–ε) turbulence model via a user-defined function (UDF) over Reynolds number (Re) range of (10,000-35,000). Numerical results indicated that the average Nusselt number ratio increases as Reynolds number and volume concentration of the nanoparticles increase for all values of the channel aspect ratio. The results indicated that the maximum enhancement of the heat transfer coefficient (benefit) achieved is 94.69% at AR=0.5, along with the lowest increase of pressure drop (penalty) of 13.1%. The highest performance evaluation criterion (PEC) of 1.64 is found at AR=0.5, Re=35,000, and 5% concentration.

scholarly journals Heat transfer and fluid flow of Biodiesel at a backward-Facing step

2020 ◽  
Vol 307 ◽  
pp. 01019
Author(s):  
Fetta Danane ◽  
Rahma Bessah ◽  
Omar Mahfoud ◽  
Ahlem Boudiaf ◽  
Aida.Cherifa Ahmia ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Boundary Conditions ◽  
Rectangular Channel ◽  
Three Dimensional ◽  
Waste Cooking Oil ◽  
Velocity Variation ◽  
Backward Facing Step ◽  
Constant Wall Temperature

You should Three-dimensional simulation of a biodiesel fluid flow within a rectangular duct over a backward-facing step is investigated in the present paper. The fluid, which obeys to the Newtonian rheological behavior, is obtained by transformation of Algerian waste cooking oil into a biodiesel. Flow through a rectangular channel subjected to a constant wall temperature or constant heat flux as boundary conditions. The partial differential equations governing fluid flow and heat transfer are solved by the Fluent CFD computational code based on the Finite Volume Method. The numerical experiments are carried out to examine the effect of the Reynolds number by fluid inlet velocity variation for the two boundary conditions. The results are analyzed through the distribution of the temperature and the velocity contours. The variation of the Reynolds number and boundary conditions affects greatly the heat transfer and the fluid flow, in particular near the step region.

Computational and Experimental Study of Enhanced Laminar Flow Heat Transfer in Three-Dimensional Sinusoidal Wavy-Plate-Fin Channels

2003 ◽  
Author(s):  
Jiehai Zhang ◽  
Arun Muley ◽  
Joseph B. Borghese ◽  
Raj M. Manglik
Keyword(s):  
Heat Transfer ◽  
Flow Behavior ◽  
Computational Simulation ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Staggered Grid ◽  
Uniform Heat Flux ◽  
Complex Flow ◽  
Constant Property ◽  
Fin Efficiency

Enhanced heat transfer characteristics of low Reynolds number airflows in three-dimensional sinusoidal wavy plate-fin channels are investigated. For the computational simulation, steady state, constant property, periodically developed, laminar forced convection is considered with the channel surface at the uniform heat flux condition; the wavy-fin is modeled by its two asymptotic limits of 100% and zero fin efficiency. The governing equations are solved numerically using finite-volume techniques for a non-orthogonal, non-staggered grid. Computational results for velocity and temperature distribution, isothermal Fanning friction factor f and Colburn factor j are presented for airflow rates in the range of 10 ≤ Re ≤ 1500. The numerical results are further compared with experimental data, with excellent agreement, for two different wavy-fin geometries. The influence of fin density on the flow behavior and the enhanced convection heat transfer are highlighted. Depending on the flow rate, a complex flow structure is observed, which is characterized by the generation, spatial growth and dissipation of vortices in the trough region of the wavy channel. The thermal boundary layers on the fin surface are periodically disrupted, resulting in high local heat fluxes. The overall heat transfer performance is improved considerably, compared to the straight channel with the same cross-section, with a relatively smaller increase in the associated pressure drop penalty.

A Numerical Investigation Into the Heat Transfer Performance and Particle Dynamics of a Compressible, Highly Mass Loaded, High Reynolds Number, Particle Laden Flow

2021 ◽  
Author(s):  
Kyle Hassan ◽  
Robert F. Kunz ◽  
David Hanson ◽  
Michael Manahan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Computational Model ◽  
High Reynolds Number ◽  
Heat Transfer Performance ◽  
Particle Dynamics ◽  
Transfer Performance ◽  
Temperature Distributions ◽  
High Reynolds ◽  
Particle Laden Flow

Abstract In this work, we study the heat transfer performance and particle dynamics of a highly mass loaded, compressible, particle-laden flow in a horizontally-oriented pipe using an Eulerian-Eulerian (two-fluid) computational model. An attendant experimental configuration [1] provides the basis for the study. Specifically, a 17 bar co-flow of nitrogen gas and copper powder are modeled with inlet Reynolds numbers of 3×104, 4.5×104, and 6×104 and mass loadings of 0, 0.5, and 1.0. Eight binned particle sizes were modeled to represent the known powder properties. Significant settling of all particle groups are observed leading to asymmetric temperature distributions. Wall and core flow temperature distributions are observed to agree well with measurements. In high Reynolds number cases, the predictions of the multiphase computational model were satisfactorily aligned with the experimental results. Low Reynolds number model predictions were not as consistent with the experimental measurements.

INVESTIGATION ON HEAT TRANSFER ENHANCEMENT IN A CORRUGATED FIN-AND-TUBE COMPACT HEAT EXCHANGER

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Ahmadali Gholami ◽  
Mazlan A. Wahid ◽  
Hussein A. Mohammed ◽  
A. Saat ◽  
M. Y. M. Fairus ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Pressure Loss ◽  
Boundary Layer Separation ◽  
Performance Criteria ◽  
Recirculation Region ◽  
Moderate Pressure ◽  
Compact Heat Exchangers ◽  
Heat Transfer Augmentation

Heat transfer augmentation and pressure loss penalty in the fin-and-tube compact heat exchangers (FTCHEs) with the corrugated shape as a special form of the fin are numerically investigated to improve heat transfer performance criteria in low Reynolds numbers. The corrugated fin as the newly design of fin pattern is presented in this study. The influence of applying corrugated design adjustments on the thermal and hydraulic characteristics of air flow are analyzed on the in-line tube arrangements. The performance of air-side heat transfer and fluid flow is investigated by numerical simulation for Reynolds number ranging from Re = 400 to 800 based on the tube collar diameter, with the corresponding frontal air velocity ranging from 0.35 to 0.72 m/s. The outcomes of simulation revealed that the corrugated fin could significantly improve the heat transfer augmentation of the FTCHEs with a moderate pressure loss penalty. The computational results indicated that some eddies were developed behind the fluted domain of corrugated finwhich produce some disruptions to fluid flow and enhance heat transfer compared with plain fin. The corrugated form of fins could enhance the thermal mixing of the fluid, delay the boundary layer separation, and reduce the size of the wake and the recirculation region behind tubes compared with the conventional form of the fin at the range of Reynolds number used in this study. In addition, the results showed that the average Nusselt number for the FTCHE with corrugated fin increased by 7.05–10.0% over the baseline case and the corresponding pressure loss decreased by 5.0–6.2%.

Sign in / Sign up

Export Citation Format

Share Document