Debye Huckel Linear Approximation Research Articles

Entropy generation optimization for the electroosmotic MHD fluid flow over the curved stenosis artery in the presence of thrombosis

The present study deals with the entropy generation analysis on the flow of an electrically conductive fluid (Blood) with hbox {Al}_2hbox {O}_3-suspended nanoparticles through the irregular stenosed artery with thrombosis on the catheter. The fluid flow can be actuated by the interactions of different physical phenomena like electroosmosis, radiation, Joule heating and a uniform radial magnetic field. The analysis of different shapes and sizes of the nanoparticle is considered by taking the Crocine model. The velocity, temperature, and concentration distributions are computed using the Crank–Nicholson method within the framework of the Debye–Huckel linearization approximation. In order to see how blood flow changes in response to different parameters, the velocity contour is calculated. The aluminium oxide nanoparticles employed in this research have several potential uses in biomedicine and biosensing. The surface’s stability, biocompatibility, and reactivity may be enhanced by surface engineering, making the material effective for deoxyribonucleic acid sensing. It may be deduced that the velocity profile reduces as the nanoparticle’s size grows while depicts the reverse trend for the shape size. In a region close to the walls, the entropy profile decreases, while in the region in the middle, it rises as the magnetic field parameter rises. The present endeavour can be beneficial in biomedical sciences in designing better biomedical devices and gaining insight into the hemodynamic flow for treatment modalities.

Regulation of thermo-electro-magneto dynamics in course of peristalsis

The effect of heat transfer on Couple-Stress fluid’s unsteady peristaltic motion is theoretically studied in this paper using applied electric and magnetic fields. Thermal analysis is carried out in the presence of fluid friction-induced viscous dissipation and Joule heating. The potential distribution is examined using the Debye-Huckel linearization approximation. The governing equation’s complexity is decreased using the lubrication theory. The dynamics of electroosmosis and peristaltic pumping are examined for the velocity field, temperature field, pressure distribution, and streamlines. The effects of electrical double layer (EDL) on flow, pumping, and thermal properties have been calculated. Numerical computations have been done to provide the graphical depiction and to explain the model’s outcomes. This model can be used to design a variety of microfluidic gadgets and intelligent micropumps for combining chemicals and ionic liquids.

Heat transfer and electro-osmotic analysis on peristaltic pumping of a fractional second-grade fluid through a cylindrical tube

Most of the earlier studies intended on the peristaltic pumping of non-Newtonian fluids via channels/tubes to better know the flow activities of flowing systems. The extant effort is modeled to examine the peristaltic motion of the viscoelastic fluid through a cylindrical tube to characterize the rheological features of blood in the vascular system by incorporating the electro-osmotic phenomenon. Caputo’s definition provides analytical solutions to the dilemma. To evaluate the potential function, the Debye–Huckel linearization approximation is utilized. The long-wavelength [Formula: see text] and low Reynolds number approximations [Formula: see text] are used to simplify the simultaneous equations. The effects of physical constraints depicting the flow phenomena are obtained and conferred via graphs. The impact of several regulatory elements is deliberated and exposed in a succession of figures. The significant outcome of the result is that the pressure gradient is consistently enhanced as the external electric field strength increases. It is also observed that the growing applied electric field strength can control the negative value of the pressure gradient. This work is relevant to the electrophoresis in hematology, electrohydrodynamic therapy, and biometric electro-osmotic pumps. The present results provide a significant baseline for experiment analyses and more general models of microvascular blood flow.

Electroosmosis-Optimized Thermal Model for Peristaltic Transportation of Thermally Radiative Magnetized Liquid with Nonlinear Convection.

The present study addresses the heat transfer efficiency and entropy production of electrically conducting kerosene-based liquid led by the combined impact of electroosmosis and peristalsis mechanisms. Effects of nonlinear mixed convection heat transfer, temperature-dependent viscosity, radiative heat flux, electric and magnetic fields, porous medium, heat sink/source, viscous dissipation, and Joule heating are presented. The Debye–Huckel linearization approximation is employed in the electrohydrodynamic problem. Mathematical modeling is conducted within the limitations of δ << 1 and Re → 0. Coupled differential equations after implementing a lubrication approach are numerically solved. The essential characteristics of the production of entropy, the factors influencing it, and the characteristics of heat and fluid in relation to various physical parameters are graphically evaluated by assigning them a growing list of numeric values. This analysis reveals that heat transfer enhances by enhancing nonlinear convection and Joule heating parameters. The irreversibility analysis ensures that the minimization of entropy generation is observed when the parameters of viscosity and radiation are held under control. Fluid velocity can be regulated by adjusting the Helmholtz–Smoluchowski velocity and magnetic field strength.

Heat transfer of nanofluid with electroviscous effect in MHD-based microannulus

Thermally fully developed electrokinetic flow of nanofluid is investigated in a microannulus under the effect of electromagnetic field. The electroviscous effect on heat transfer of nanofluid is analyzed theoretically. Based on the Debye–Huckel linearization approximation, the analytical expressions of electrical potential, flow velocity and streaming potential are derived. Then, the temperature distribution of nanofluid is obtained by the finite difference numerical method. The influences of nanoparticle volume fraction, magnetic field and radius ratio on streaming potential and temperature are discussed in detail. It is revealed that the streaming potential can be enhanced with the increase in magnetic field strength. For various nanoparticle volume fractions, a threshold value of magnetic field strength can be obtained. Besides, local fluid temperature can effectively be enhanced with the increase in nanoparticle volume fraction. Finally, the effect of convective heat transfer can be regulated by the nanoparticle volume fraction, magnetic field strength and microannulus scale. The present work can provide a theoretical contribution to the flow and heat transfer of nanofluid in microannulus.

Peristaltically Induced Electroosmotic Flow of Jeffrey Fluid with Zeta Potential and Navier-Slip at the Wall

This paper concern with the electro-osmotically modulated peristaltic of Jeffrey fluid with zeta potential and Navier-slip boundary condition at the channel wall. The Poisson-Boltzmann equation for electrical potential distribution is assumed to accommodate the electrical double layer. Poisson-Boltzmann equations are simplified by using Debye-Huckel linearization approximation. The closed form analytical solutions are calculated by using low Reynolds number and long wavelength assumptions. Influence of various parameters like electro-osmotic, Jeffrey fluid parameter, Slip parameter and Zeta potential on the flow are discussed through the nature of graphs.

Electroosmotic flow of Phan-Thien–Tanner fluids at high zeta potentials: An exact analytical solution

We present a mathematical model to study the electroosmotic flow of a viscoelastic fluid in a parallel plate microchannel with a high zeta potential, taking hydrodynamic slippage at the walls into account in the underlying analysis. We use the simplified Phan-Thien–Tanner (s-PTT) constitutive relationships to describe the rheological behavior of the viscoelastic fluid, while Navier’s slip law is employed to model the interfacial hydrodynamic slip. Here, we derive analytical solutions for the potential distribution, flow velocity, and volumetric flow rate based on the complete Poisson–Boltzmann equation (without considering the frequently used Debye–Hückel linear approximation). For the underlying electrokinetic transport, this investigation primarily reveals the influence of fluid rheology, wall zeta potential as modulated by the interfacial electrochemistry and interfacial slip on the velocity distribution, volumetric flow rate, and fluid stress, as well as the apparent viscosity. We show that combined with the viscoelasticity of the fluid, a higher wall zeta potential and slip coefficient lead to a phenomenal enhancement in the volumetric flow rate. We believe that this analysis, besides providing a deep theoretical insight to interpret the transport process, will also serve as a fundamental design tool for microfluidic devices/systems under electrokinetic influence.

Electroosmotic flow of a power law fluid in an elliptic microchannel

Abstract In this paper the two dimensional electroosmotic flow of a non-Newtonian fluid governed by the power law model is studied for circular and elliptic microchannels. The electric potential and the velocity distribution inside the microchannel are solved without invoking the Debye–Huckel linear approximation. The solutions are sought for different aspect ratio (E), power law index (n), Debye–Huckel parameter (K) and the wall zeta potential (ζ). The effect of these parameters is studied on the ratio of flow rates Q/Qcir and friction parameter. The comparison of a circular geometry (E = 1) and an elliptical geometry (E ≠ 1) is made on an equal cross sectional area basis. Elliptic microchannels always reduce the flow rate when compared to circular microchannels. This reduction is much more significant at lower values of K and ζ. Shear thickening fluids affect the reduction in flow rates much more when compared to shear thinning ones. This reduction in flow rates becomes larger as the aspect ratio increases. The frictional parameter increases with K and ζ for all E. Shear thickening fluids have larger frictional parameter values compared to shear thinning fluids.

Electroosmotic flow of power-law fluids at high zeta potentials

In this paper, a mathematical model for electroosmotic flow of power-law fluids in a rectangular microchannel at high zeta potential is analyzed. The electric double layer (EDL) potential distribution is considered without Debye Huckel linear approximation. Numerical solution is obtained to analyze the fluid flow behavior. Parametric studies are conducted to assess the variation of shear stress, viscosity and volumetric flow rates of various values of flow behavior index ( n). Computed results are used to explicate the possibility of using a relatively pseudoplastic fluid inside microchannel to obtain higher volumetric flow rates.

On electroviscous effects in microchannels

This paper contains results of a theoretical investigation on the effect of the diffusive electric double layer (EDL) at the solid–liquid interface on liquid flow through a microchannel between two parallel plates. Unlike previous works, the electrical charge connected with the EDL at the inlet of a channel is accounted for. The Debye–Huckel linear approximation of the surface potential distribution is used to describe the EDL field near the solid–liquid interface. The electrokinetic distance is assumed to be arbitrary. The electrical body force resulting from the double layer field is considered in the equation of motion. This equation is solved for steady-state flow. Effects of the EDL field on the apparent viscosity are discussed.