Increase In Viscoelastic Parameter Research Articles

Unsteady EMHD free convective second grade fluid flow past an exponentially accelerated vertical porous plate

This paper presents a detailed account of unsteady, incompressible, viscous, electrically conducting, unidirectional, free convective second grade fluid through an exponentially accelerated vertically infinite plate with both applied electric field and magnetic field being present. The equation of motion and energy manifested as nonlinear partial differential equation are represented as algebraic equations using implicit finite difference scheme and solved numerically by implementing the damped-Newton method. With the help of the momentum and energy equation, we defined the expressions for skin friction and Nusselt number. The cases n = 1(constant acceleration) and n = 0.5(variable acceleration) are also taken into consideration. The solution obtained is eventually simulated using MATLAB and the resulting graphs representing the influence of non-dimensional parameters on flow field and temperature field are discussed thoroughly. We have also validated the results obtained from the present methodology with the results obtained from already existing methodologies under some limited cases. It is interesting to note that when the plate is being cooled by free convection current, with increase in viscoelastic parameter the viscous forces are dominated by the elastic effects which results in accelerating the velocity flow profile. For comparatively smaller values of Ec the temperature distribution decreases with increasing Re as the suction propagation facilitates decrease in boundary layer thickness which consequently enhances heat transfer rate. The effect of Ec is to raise the temperature profile due to enhancement in viscous dissipation effects. Practically, the combined effects of the physical parameters are remarkably important in various engineering, medical and industrial applications.

Chemical reaction with aligned magnetic field effects on unsteady MHD Kuvshinski fluid flow past an inclined porous plate in the presence of radiation and Soret effects

AbstractThe present paper studies the effect of a chemical reaction and aligned magnetic field on an unsteady magnetohydrodynamic free convection Kuvshinski fluid flow past an inclined plate through a porous medium in the presence of Soret and radiation. The plate is assumed to be embedded in a uniform porous medium and moves with a constant velocity in the flow direction in the presence of a transverse magnetic field. The systems of nondimensional governing linear partial differential equations are solved analytically by using the perturbation technique. The influences of various nondimensional parameters on the velocity, the temperature, and the concentration are discussed, as also the effects of various parameters on the skin‐friction coefficient and the rate of heat transfer in the form of Nusselt number and rate of mass transfer in the form of Sherwood number at the surface. Velocity distribution is observed to increase with an increase in viscoelastic parameter and Soret parameter, whereas it shows reverse effects in the case of the aligned magnetic field, inclined parameter, magnetic parameter, the temperature diminishes with the increase of radiation parameter and heat absorption parameter.

Influence of gravity on torsional surface waves in a dissipative medium

The present paper deals with the possibilities of propagation of torsional surface waves in a viscoelastic medium under gravity field. During the study it will observe that the increase in gravity parameter will increase the velocity of the wave, the increase in viscoelastic parameter, decrease the velocity of the wave until the product of angular frequency and viscoelastic parameter is less than unity. It also notes that as the velocity increases, the curve becomes asymptotic in nature when the period of oscillation increases. In fact the maximum damping in velocity has been identified at this cut off point which may be considered as the point where a viscoelastic material becomes a viscous medium.The absorption coefficients have also been calculated for different values of the viscoelastic parameter and gravity field.

Significant consequences of heat generation/absorption and homogeneous-heterogeneous reactions in second grade fluid due to rotating disk

Abstract Flow of second grade fluid by a rotating disk with heat and mass transfer is discussed. Additional effects of heat generation/absorption are also analyzed. Flow is also subjected to homogeneous-heterogeneous reactions. The convergence of computed solution is assured through appropriate choices of initial guesses and auxiliary parameters. Investigation is made for the effects of involved parameters on velocities (radial, axial, tangential), temperature and concentration. Skin friction and Nusselt number are also analyzed. Graphical results depict that an increase in viscoelastic parameter enhances the axial, radial and tangential velocities. Opposite behavior of temperature is observed for larger values of viscoelastic and heat generation/absorption parameters. Concentration profile is increasing function of Schmidt number, viscoelastic parameter and heterogeneous reaction parameter. Magnitude of skin friction and Nusselt number are enhanced for larger viscoelastic parameter.

Three-dimensional flow of an elastico-viscous nanofluid with chemical reaction and magnetic field effects

Magnetohydrodynamic (MHD) three-dimensional flow of an elastico-viscous nanofluid under the influence of mass transfer and chemical reaction is studied. The flow is produced by a bidirectional stretching sheet. Effects of thermophoresis and Brownian motion are also present. In the presence of constant applied magnetic field, the fluid is electrically conducting. Using appropriate transformations, the governing nonlinear partial differential equations are converted into highly nonlinear coupled ordinary differential equations. Homotopy Analysis method (HAM) is employed to find the series solution of the acquired system of equations. h-curves have been drawn to discuss the convergence of HAM solution. Effects of velocity, temperature and concentration profiles on the emerging important parameters is portrayed and discussed graphically. Numerical values of local Nusselt number, skin friction and Sherwood number with different parameters are calculated and examined. It is observed that temperature profile increases and concentration profile decreases with increasing values of Brownian motion parameter Nb. It is also noticed that both velocity components decrease with an increase in viscoelastic parameter k.

A numerical study of free convection heat and mass transfer in a Rivlin–Ericksen viscoelastic flow past an impulsively started vertical plate with variable temperature and concentration

In this paper an analysis of the effect of viscoelasticity on the natural free convective unsteady laminar heat transfer fluid flowing past an impulsively started vertical plate with variable surface temperature and mass concentration. The Rivlin–Ericksen model is employed to simulate the rheological liquids encountered in cooling of electronic devices, polymer solutions, hydrocarbons and chemical engineering processes. The transport equations employed in the flow are governed by a coupled non-linear system of partial differential equations and include the five parameters. viz. Gr (the thermal Grashof number), Gm (the solutal Grashof number), Γ (viscoelastic parameter), Pr (the fluid Prandtl number) and Sc (the Schmidt number). The transformed two-point boundary value problem is solved numerically using the Gauss-Seidel process of the finite element method subjected to appropriate boundary conditions. Numerical results are obtained to study the influence of viscoelasticity parameter (Γ), surface temperature power law exponent (m) and surface concentration power law (n) on the velocity, temperature, concentration fields, the local skin-friction (τx), the Nusselt number (Nux) and the Sherwood number (Shx). The results indicate that the velocity, temperature and concentration fields decrease with increase in viscoelastic parameter. Likewise, the skin friction coefficient, the local Nusselt number and Sherwood number increase with the increase in viscoelastic parameter for X⩽0.48.

Mixed convection flow of second grade fluid along a vertical stretching flat surface with variable surface temperature

In the present study we have explored the effects of thermal buoyancy on flow of a viscoelastic second grade fluid past a vertical, continuous stretching sheet of which the velocity and temperature distributions are assumed to vary according to a power-law form. The governing differential equations are transformed into dimensionless form using appropriate transformations and then solved numerically. The methods here employed are (1) the perturbation method together with the Shanks transformation, (2) the local non-similarity method with second level of truncation and (3) the implicit finite difference method for values of ξ ( = Grx/Rex2, defined as local mixed convection parameter) ranging in [0, 10]. The comparison between the solutions obtained by the aforementioned methods found in excellent agreement. Effects of the elasticity parameter λ on the skin-friction and heat transfer coefficients have been shown graphically for the fluids having the values of the Prandtl number equal to 0.72, 7.03 and 15.0. Effects of the viscoelastic parameter and the mixed convection parameter, ξ, on the temperature and velocity fields have also been studied. We notice that with the increase in visco-elastic parameter λ, velocity decreases whereas temperature increases and that velocity gradient is higher than that of temperature.

A Model for the Lubrication Mechanism in Knee Joint Replacement

Analytical studies are presented for the understanding of the lubrication mechanism occuring in knee joint replacement under restricted motion. The idealised model has been shown to produce results consistent with those in normal situations. Effects of increase in viscoelastic parameter of the lubricant are similar to those of increase in the concentration of hyaluronic acid molecules in synovial fluid. Slip velocity occuring at the poroelastic boundary helps in normal functioning of the joints.