Joule Heating Induced Thermal and Hydrodynamic Development in Microfluidic Electroosmotic Flow

2004 ◽  
Author(s):  
G. Y. Tang ◽  
C. Yang ◽  
C. J. Chai ◽  
H. Q. Gong
Keyword(s):  
Mass Transport ◽  
Joule Heating ◽  
Electroosmotic Flow ◽  
Planck Equation ◽  
Liquid Solution ◽  
Ionic Concentration ◽  
Temperature Fields ◽  
Temperature Dependent ◽  
Navier Stokes Equation ◽  
Species Transport

Joule heating is present in electrokinetically driven flow and mass transport in microfluidic systems. Specifically, in the cases of high applied voltages and concentrated buffer solutions, the thermal management may become a problem. In this study, a mathematical model is developed to describe the Joule heating and its effects on electroosmotic flow and mass species transport in microchannels. The proposed model includes the Poisson equation, the modified Navier-Stokes equation, and the conjugate energy equation (for the liquid solution and the capillary wall). Specifically, the ionic concentration distributions are modeled using (i) the general Nernst-Planck equation, and (ii) the simple Boltzmann distribution. These governing equations are coupled through temperature-dependent phenomenological thermal-physical coefficients, and hence they are numerically solved using a finite-volume based CFD technique. A comparison has been made for the results of the ionic concentration distributions and the electroosmotic flow velocity and temperature fields obtained from the Nernst-Planck equation and the Boltzmann equation. The time and spatial developments for both the electroosmotic flow fields and the Joule heating induced temperature fields are presented. In addition, sample species concentration is obtained by numerically solving the mass transport equation, taking into account of the temperature-dependent mass diffusivity and electrophoresis mobility. The results show that the presence of the Joule heating can result in significantly different electroosomotic flow and mass species transport characteristics.

Numerical Simulation of Joule Heating Effect on Electroosmotic Flow and Electrokinetic Mass Transport in Microchannels

Volume 3 ◽  
2004 ◽  
Author(s):  
Gongyue Tang ◽  
Chun Yang ◽  
Cheekiong Chai ◽  
Haiqing Gong
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Mass Transport ◽  
Joule Heating ◽  
Electroosmotic Flow ◽  
Stokes Equations ◽  
Heating Effect ◽  
Species Transport ◽  
Joule Heating Effect ◽  
Numerical Predictions

This study presents a numerical simulation of Joule heating effect on electroosmotic flow and mass species transport in microchannels, which has direct applications in the capillary electrophoresis based Biochip technology. The proposed model includes the Poisson-Boltzmann equation, the modified Navier-Stokes equations, the conjugate energy equation, and the mass species transport equation. The numerical predictions show that the time development for both the electroosmotic flow field and the Joule heating induced temperature field are less than 1 second. The Joule heating induced temperature field is strongly dependent on channel size, electrolyte concentration, and applied electric field strength. The simulations reveal that the presence of Joule heating can result in significantly different characteristics of the electroosmotic flow and electrokinetic mass transport in microchannels.

Thermally Fully Developed Electroosmotic Flow of Power-Law Fluids in a Circular Microchannel

2013 ◽  
Vol 29 (4) ◽  
pp. 609-616 ◽  
Author(s):  
Y.-J. Sun ◽  
Y.-J. Jian ◽  
L. Chang ◽  
Q.-S. Liu
Keyword(s):  
Power Law ◽  
Joule Heating ◽  
Electroosmotic Flow ◽  
Flow Behavior ◽  
Mathematic Model ◽  
Dimensionless Temperature ◽  
Fluid Temperature ◽  
Navier Stokes Equation ◽  
Power Law Fluids ◽  
Behavior Index

ABSTRACTThis study presents a thermally fully developed electroosmotic flow of the non-Newtonian power-law fluids through a circle microchannel. A rigorous mathematic model for describing the Joule heating in an electroosmotic flow including the Poisson Boltzmann equation, the modified Navier Stokes equation and the energy equation is developed. The semi-analytical solutions of normalized velocity and temperature are derived. The velocity profile is computed by numerical integrate, and the temperature distribution is obtained by finite difference method. Results show that the velocity profiles depend greatly on the fluid behavior index n and the nondimensional electrokinetic width K. For a specified value of K, the axial velocity increases with a decrease in n, and the same trend for the effect of K on the velocity can be found for a specified value of n. Moreover, the dimensionless temperature is governed by three parameters, namely, the flow behavior index n, the nondimensional electrokinetic width K, and the dimen-sionless Joule heating parameter G. The variations of radial fluid temperature distributions with different parameters are investigated.

Electroosmotic Flow and Mass Species Transport in a Microcapillary Under Influences of Joule Heating

2003 ◽  
Author(s):  
Gongyue Tang ◽  
Chun Yang ◽  
Cheekiong Chai ◽  
Haiqing Gong
Keyword(s):  
Joule Heating ◽  
Electroosmotic Flow ◽  
Mathematic Model ◽  
Transfer Coefficients ◽  
Mass Transfer Equation ◽  
Buffer Solution ◽  
Species Transport ◽  
Heat Transfer Coefficients ◽  
Poisson Boltzmann ◽  
Poisson Boltzmann Equation

This study presents a numerical analysis of Joule heating effect on the electroosmotic flow and species transport, which has a direct application in the capillary electrophoresis based BioChip technology. A rigorous mathematic model for describing the Joule heating in an electroosmotic flow including Poisson-Boltzmann equation, modified Navier-Stokers equations and energy equation is developed. All these equations are coupled together through the temperature-dependent parameters. By numerically solving aforementioned equations simultaneously, the electroosmotic flow field and the temperature distributions in a cylindrical microcapillary are obtained. A systematic study is carried out under influences of different geometry sizes, buffer solution concentrations, applied electric field strengths, and heat transfer coefficients. In addition, sample species transport in a microcapillary is also investigated by numerically solving the mass transfer equation with consideration of temperature-dependant diffusion coefficient and electrophoresis mobility. The characteristics of the Joule heating, electroosmotic flow, and sample species transport in microcapillaries are discussed. The simulations reveal that the presence of the Joule heating could have a great impact on the electroosmotic flow and sample species transport.

Electroosmotic Flow Separation in a Corrugated Micro-Channel: A Numerical Study

2018 ◽  
Author(s):  
A. Banerjee ◽  
A. K. Nayak
Keyword(s):  
Flow Separation ◽  
Electroosmotic Flow ◽  
Numerical Study ◽  
Vortex Formation ◽  
Planck Equation ◽  
Threshold Value ◽  
Vital Role ◽  
Computational Domain ◽  
Navier Stokes Equation ◽  
Major Interest

A two dimensional numerical study is made on the electroosmotic flow separation and vortex formation in a symmetric wavy micro/nano channel filled with a Newtonian, incompressible electrolyte. Flow domain is modelled by two superimposed sinusoidal functions which is mapped into a simpler rectangular computational domain using a suitable coordinate transformation. The distributions of flow field and electric potential are obtained by solving a coupled set of nonlinear governing equations involving Poisson-Nernst-Planck equation and Navier-Stokes equation using finite volume method. Threshold value of the scaled wave amplitude for flow reversal is obtained for fixed Debye-Hückel parameter and solute strength where flow separation plays a vital role for micromixing which can be a major interest for many research problems of biological flows.

scholarly journals An Incompressible Polymer Fluid Interacting with a Koiter Shell

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Dominic Breit ◽  
Prince Romeo Mensah
Keyword(s):  
Moving Boundary ◽  
Classical Model ◽  
Elastic Shell ◽  
Planck Equation ◽  
Navier Stokes ◽  
Flexible Shell ◽  
Navier Stokes Equation ◽  
Shell System ◽  
Forward Equation ◽  
Polymer Fluid

AbstractWe study a mutually coupled mesoscopic-macroscopic-shell system of equations modeling a dilute incompressible polymer fluid which is evolving and interacting with a flexible shell of Koiter type. The polymer constitutes a solvent-solute mixture where the solvent is modelled on the macroscopic scale by the incompressible Navier–Stokes equation and the solute is modelled on the mesoscopic scale by a Fokker–Planck equation (Kolmogorov forward equation) for the probability density function of the bead-spring polymer chain configuration. This mixture interacts with a nonlinear elastic shell which serves as a moving boundary of the physical spatial domain of the polymer fluid. We use the classical model by Koiter to describe the shell movement which yields a fully nonlinear fourth order hyperbolic equation. Our main result is the existence of a weak solution to the underlying system which exists until the Koiter energy degenerates or the flexible shell approaches a self-intersection.

scholarly journals Simultaneous impacts of Joule heating and variable heat source/sink on MHD 3D flow of Carreau-nanoliquids with temperature dependent viscosity

2019 ◽  
Vol 8 (1) ◽  
pp. 356-367 ◽  
Author(s):  
J. V. Ramana Reddy ◽  
V. Sugunamma ◽  
N. Sandeep
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Joule Heating ◽  
Uniform Space ◽  
Weissenberg Number ◽  
Physical Parameters ◽  
Temperature Dependent ◽  
3D Flow ◽  
Temperature Dependent Viscosity ◽  
Source Sink

Abstract The 3D flow of non-Newtonian nanoliquid flows past a bidirectional stretching sheet with heat transfer is investigated in the present study. It is assumed that viscosity of the liquid varies with temperature. Carreau non-Newtonain model, Tiwari and Das nanofluid model are used to formulate the problem. The impacts of Joule heating, nonlinear radiation and non-uniform (space and temperature dependent) heat source/sink are accounted. Al-Cu-CH3OH and Cu-CH3OH are considered as nanoliquids for the present study. The solution of the problem is attained by the application of shooting and R.K. numerical procedures. Graphical and tabular illustrations are incorporated with a view of understanding the influence of various physical parameters on the flow field. We eyed that using of Al-Cu alloy nanoparticles in the carrier liquid leads to superior heat transfer ability instead of using only Aluminum nanoparticles. Weissenberg number and viscosity parameter have inclination to exalt the thermal field.

Sign in / Sign up

Export Citation Format

Share Document