Role of Joule Heating in Electro-Assisted Processes: A Boundary Layer Approach for Rectangular Electrodes

2013 ◽  
Vol 11 (2) ◽  
pp. 815-823 ◽  
Author(s):  
Mario A. Oyanader ◽  
Pedro E. Arce ◽  
James D. Bolden
Keyword(s):  
Boundary Layer ◽  
Heat Generation ◽  
Joule Heating ◽  
Boundary Layer Thickness ◽  
Electrokinetic Remediation ◽  
Boundary Layer Flows ◽  
Approximation Approach ◽  
Convective Mixing ◽  
Layer Flow

Abstract An analysis for boundary layer flows caused by natural convection due to heat generation caused by the Joule heating effect is presented. The integral approximation approach developed by Von Karman is used to model the boundary layer flow in the system. Effects of the heat generation on temperature and velocity profiles as well as on the boundary layer thickness are discussed, and their implication for possible convective mixing effects near the electrode region is highlighted. These are important pieces of information when designing applications in electrokinetic remediation and separation of biomolecules.

scholarly journals Magnetohydrodynamic (MHD) Boundary Layer Flow Past a Wedge with Heat Transfer and Viscous Effects of Nanofluid Embedded in Porous Media

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Wubshet Ibrahim ◽  
Ayele Tulu
Keyword(s):  
Boundary Layer ◽  
Porous Media ◽  
Brownian Motion ◽  
Prandtl Number ◽  
Boundary Layer Flow ◽  
Boundary Layer Thickness ◽  
Lewis Number ◽  
Mhd Boundary Layer ◽  
Layer Flow ◽  
Mhd Boundary Layer Flow

The problem of two-dimensional steady laminar MHD boundary layer flow past a wedge with heat and mass transfer of nanofluid embedded in porous media with viscous dissipation, Brownian motion, and thermophoresis effect is considered. Using suitable similarity transformations, the governing partial differential equations have been transformed to nonlinear higher-order ordinary differential equations. The transmuted model is shown to be controlled by a number of thermophysical parameters, viz. the pressure gradient, magnetic, permeability, Prandtl number, Lewis number, Brownian motion, thermophoresis, and Eckert number. The problem is then solved numerically using spectral quasilinearization method (SQLM). The accuracy of the method is checked against the previously published results and an excellent agreement has been obtained. The velocity boundary layer thickness reduces with an increase in pressure gradient, permeability, and magnetic parameters, whereas thermal boundary layer thickness increases with an increase in Eckert number, Brownian motion, and thermophoresis parameters. Greater values of Prandtl number, Lewis number, Brownian motion, and magnetic parameter reduce the nanoparticles concentration boundary layer.

scholarly journals Analysis of Boundary Layer Flow and Heat Transfer for two Classes of Viscoelastic Fluid Over a Stretching Sheet with Heat Generation or Absorption

1970 ◽  
Vol 46 (4) ◽  
pp. 451-456 ◽  
Author(s):  
K Bhattacharyya ◽  
MS Uddin ◽  
GC Layek ◽  
W Ali Pk
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Viscoelastic Fluid ◽  
Heat Generation ◽  
Boundary Layer Flow ◽  
Stretching Sheet ◽  
Second Grade ◽  
Grade Fluid ◽  
Heat Generation Or Absorption ◽  
Layer Flow

In this paper, we obtained solutions of boundary layer flow and heat transfer for two classes of viscoelastic fluid over a stretching sheet with internal heat generation or absorption. In the analysis, we consider second-grade fluid and Walter's liquid B. The governing equations are transformed into self-similar ordinary differential equations by similarity transformations. The flow equation relating to momentum is solved analytically and then the heat equation using the Kummer's function. The analysis reveals that for the increase in magnitude of viscoelastic parameter both the velocity and temperature for a fixed point increase for second-grade fluid and both decrease for Walter's liquid B. Due to increase in Prandtl number and heat sink parameter, the thermal boundary layer thickness reduces, whereas increasing heat source parameter increases that thickness. Key words: Boundary layer flow; Heat transfer; Viscoelastic fluid; Stretching sheet; Heat generation or absorption DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9590 BJSIR 2011; 46(4): 451-456

A Theory for Fine Particle Deposition in Two-Dimensional Boundary Layer Flows and Application to Gas Turbines

1982 ◽  
Vol 104 (1) ◽  
pp. 69-76 ◽  
Author(s):  
M. Mengu¨turk ◽  
E. F. Sverdrup
Keyword(s):  
Boundary Layer ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Fine Particles ◽  
Magnitude Estimate ◽  
Two Dimensional ◽  
Boundary Layer Flows ◽  
Order Of Magnitude ◽  
Dimensional Boundary ◽  
Layer Flow

A theory is presented to predict deposition rates of fine particles in two-dimensional compressible boundary layer flows. The mathematical model developed accounts for diffusion due to both molecular and turbulent fluctuations in the boundary layer flow. Particle inertia is taken into account in establishing the condition on particle flux near the surface. Gravitational settling and thermophoresis are not considered. The model assumes that the fraction of particles sticking upon arrival at the surface is known, and thus, treats it as a given parameter. The theory is compared with a number of pipe and cascade experiments, and a reasonable agreement is obtained. A detailed application of the model to a turbine is also presented. Various regimes of particle transport are identified, and the range of validity of the model is discussed. An order of magnitude estimate is obtained for the time the turbine stage can be operated without requiring cleaning.

Analytical Approach of Unsteady Boundary-Layer Flows Over a Semi-Infinite Plate for All Strouhal Numbers

2010 ◽  
Vol 78 (2) ◽  
Author(s):  
Mohamed Bachiri ◽  
Ahcene Bouabdallah
Keyword(s):  
Boundary Layer ◽  
Strouhal Number ◽  
Boundary Layer Flow ◽  
Ad Hoc ◽  
Infinite Plate ◽  
Unsteady Boundary Layer ◽  
Boundary Layer Flows ◽  
Local Skin ◽  
Analytic Expressions ◽  
Layer Flow

In this paper, the unsteady boundary-layer flow over a semi-infinite flat plate is solved by means of an analytic approach. Via an ad hoc technique based on the boundary-layer flow evolution, an analytic expression of the velocity profile is proposed. The proposed formula verifies well the results given by Rayleigh, Blasius, and Williams–Rhyne for all time, thus for all Strouhal number values, which is the characteristic of the studied problem. As the main results, the local skin friction depending on a Strouhal number is given in an aim to show an explanation on the flow evolutions from the initial solution to the steady solution in the whole spatial region. This approach permits us to take many applications in engineering technology when the analytic expressions of the velocity, temperature, and matter are looked for.

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