Unsteady MHD Plane Couette-Poiseuille Flow of Fourth-Grade Fluid with Thermal Radiation, Chemical Reaction and Suction Effects

This study investigates the unsteady MHD flow of a fourth-grade fluid in a horizontal parallel plates channel. The upper plate is oscillating and moving while the bottom plate is stationary. Solutions for momentum, energy and concentration equations are obtained by the He-Laplace scheme. This method was also used by Idowu and Sani [12] and there is agreement with our results. The effect of various flow parameters controlling the physical situation is discussed with the aid of graphs. Significant results from this study show that velocity and temperature fields increase with the increase in the thermal radiation parameter, while velocity and concentric fields decrease with an increase in the chemical reaction parameter. Furthermore, velocity, temperature and concentric fields decrease with an increase in the suction parameter. It is also interesting to note that when S4 = 0, our results will be in complete agreement with Idowu and Sani [12] results. The results of this work are applicable to industrial processes such as polymer extrusion of dye, draining of plastic films etc.

Implication of fluid rheology on the Cattaneo–Christov heat flux theory for fourth grade nanofluid over a riga device with thermal radiation

This paper analyzes the influence of mixed convective fourth grade nanofluid flow by a stretchable Riga device in the presence variable thermal conductivity and mass diffusivity. Heat and mass transportation are considered with Cattaneo–Christov (CC) model. Thermal radiation and dissipation are also taken in the energy expression. Suitable transformation is employed to reduce partial differential system into nonlinear ordinary system. The governing nonlinear expression is solved via optimal homotopy analysis method. Impact of different physical variables is discussed via graphs. Velocity profile is enhanced for higher values of cross viscous parameter and fourth grade fluid variable. Fluid temperature enhances for higher estimation of thermal relaxation parameter but reverse behavior is seen for solutal concentration variable on nanoparticle concentration.

Mathematical Model and Solution for an Unsteady MHD Fourth Grade Fluid Flow over a Vertical Plate in a Porous Medium with Magnetic Field and Suction/Injection Effects

This work investigates the mathematical model and solution for an unsteady MHD fourth grade fluid flow over a vertical plate in a porous medium with the effects of the magnetic field and suction/injection parameters using Homotopy Perturbation Method. The flow is considered to satisfy the constitutive equations of fourth grade fluid flow model and because of the Homotopy Perturbation Method used, only the momentum equation with initial and boundary conditions are solved as governing equations. After initializing stability test, the convergence of the governing equations are observed graphically using the results of Homotopy Perturbation Method with the new analytical method used by Yurusoy in literature and there is a perfect agreement in results. The impact of dimensionless second, third and fourth grade parameters with the effects of magnetic field and suction/injection parameters on the velocity field are displayed graphically and discussed. Increase in suction parameter decreases the momentum boundary layer thickness while injection parameter enhances velocity distribution in the boundary layer. Magnetic field reduces velocity throughout the boundary layer because the Lorentz force which acts as retarding force reduces the boundary layer thickness.

Flow of a fourth grade fluid between rotating disks

Flow of fluids between rotating surface is encountered in many industrial, manufacturing, mixing and biological processes. These fluids are complex, exhibit various rheological characteristics, and thus follow highly nonlinear models. In this paper, we have used fourth grade fluid model to represent fluids involved in such processes. The steady flow between two coaxial rotating disks is modeled. The resulting highly nonlinear equations are solved using perturbation approach. The velocity field in three-dimensional cylindrical coordinate system is reported. The results are then simulated to present a visual understanding of the flow.