Role of Aspect Ratio and Joule Heating within the Fluid Region Near a Cylindrical Electrode in Electrokinetic Remediation: A Numerical Solution based on the Boundary Layer Model

2013 ◽  
Vol 11 (2) ◽  
pp. 687-699
Author(s):  
Mario A. Oyanader ◽  
Pedro E. Arce
Keyword(s):  
Boundary Layer ◽  
Numerical Solution ◽  
Joule Heating ◽  
Navier Stokes ◽  
Integral Model ◽  
Transfer Model ◽  
Layer Model ◽  
Navier Stokes Equation ◽  
Temperature Development

Abstract This contribution focuses on the analysis of the hydrodynamics taking place near an electrode of cylindrical geometry in electrokinetic applications. Both the temperature development conditions and Joule heating effect are included. A boundary layer approach has been used to model the hydrodynamic in the system. This is based on the heat transfer model, the continuity equation, and the Navier–Stokes equation. The resulting set of two partial differential equations mutually coupled is solved applying the Von Karman integral approximation. A numerical solution of the differential–integral model is used to illustrate the behavior of the systems under a variety of conditions.

A fast multiobjective optimization approach to S-duct scoop inlets design with both inflow and outflow

2018 ◽  
Vol 233 (9) ◽  
pp. 3381-3394
Author(s):  
Lifang Zeng ◽  
Dingyi Pan ◽  
Shangjun Ye ◽  
Xueming Shao
Keyword(s):  
Multiobjective Optimization ◽  
Total Pressure ◽  
Optimization Method ◽  
Navier Stokes ◽  
Integral Model ◽  
Optimization Approach ◽  
Navier Stokes Equation ◽  
Cross Sectional ◽  
Design Variables ◽  
Computational Fluid Dynamics Analysis

A fast multiobjective optimization method for S-duct scoop inlets considering both inflow and outflow is developed and validated. To reduce computation consumption of optimization, a simplified efficient model is proposed, in which only inflow region is simulated. Inlet pressure boundary condition of the efficient model is specified by solving an integral model with both inflow and outflow. An automated optimization system integrating the computational fluid dynamics analysis, nonuniform rational B-spline geometric representation technique, and nondominated sorting genetic algorithm II is developed to minimize the total pressure loss and distortion at the exit of diffuser. Flow field is numerically simulated by solving the Reynolds-averaged Navier–Stokes equation coupled with k–ω shear stress transport turbulence model, and results are validated to agree well with previous experiment. S-duct centreline shape and cross-sectional area distribution are parameterized as the design variables. By analyzing the results of a suggested optimal inlet chosen from the obtained Pareto front, total pressure recovery has increased from 97% to 97.4%, and total pressure distortion DC60 has decreased by 0.0477 (21.7% of the origin) at designed Mach number 0.7. The simplified efficient model has been validated to be reliable, and by which the time cost for the optimization project has been reduced by 70%.

Casimir cascades in two-dimensional turbulence

2013 ◽  
Vol 729 ◽  
pp. 364-376 ◽  
Author(s):  
John C. Bowman
Keyword(s):  
Stokes Equation ◽  
Navier Stokes ◽  
Fourth Power ◽  
Two Dimensional ◽  
Vorticity Field ◽  
Navier Stokes Equation ◽  
Small Scales ◽  
Open Question ◽  
Incompressible Navier Stokes Equation

AbstractIn addition to conserving energy and enstrophy, the nonlinear terms of the two-dimensional incompressible Navier–Stokes equation are well known to conserve the global integral of any continuously differentiable function of the scalar vorticity field. However, the phenomenological role of these additional inviscid invariants, including the issue as to whether they cascade to large or small scales, is an open question. In this work, well-resolved implicitly dealiased pseudospectral simulations suggest that the fourth power of the vorticity cascades to small scales.

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.

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