The present article examines the nonlinear stability of two viscoelastic electrified cylindrical fluids immersed in permeable media. The current structure consists of two endless vertical cylinders containing two electrified fluids. An axial unchanged electric field (EF) is applied to the entire construction; additionally, the impact of the surface tension is reflected. The main driving force for understanding this challenge has increasing significance in atmospheric and oceanic dynamics. The viscous potential theory is employed to ease the mathematical processes. The fundamental hydrodynamic equations are combined with Maxwell's equations in the quasi-static approximation to set the boundary-value problem. The appropriate boundary conditions (BCs) are expressed in a nonlinear form; this nonlinearity is achieved by addressing the linearized controlling equations of the motion. The viscoelastic impacts are considered to illustrate how the BCs produce their contributions. Consequently, the equations of motion are tackled without the effects of viscoelasticity parameters. The interface displacement consequently interacts vertically along with the cylindrical axis. The Rayleigh Helmholtz–Duffing oscillator describes the propagation of the interface between the two fluids. The non-perturbative approach (NPA), based on the He's frequency formula, transforms the typical nonlinear differential equation (NDE) into a linear one. The non-dimensional analysis reveals a lot of dimensionless physical numerals. These non-dimensional physical characteristics can be utilized to study the fundamental character of the liquid movement. They are also used to reduce the quantity of variables that are needed to comprehend the framework. A quick explanation of NPA is also presented. The stability study reveals the real/complex coefficients of the NDE. The numerical simulations show that there is a consistent solution and that the increases in the axial EF, as well as axial wavenumber, stabilize the system. The obtained findings help to understand and explain diverse nonlinear progressions that have taken place in fluid mechanics. To show the impact of the different factors and the efficiency of the stability approach, diverse PolarPlot diagrams are graphed for both actual and hypothetical portions.

The nonlinear stability of a plane interface separating two Bingham fluids and fully saturated in porous media is inspected in the existing work. The two fluids are compressed by a normal magnetic field. The two fluids have diverse viscoelasticity, densities, magnetic, and porosity medium, with the existence of surface tension at the interface. The motivation of applied physics and engineering relations has encouraged the discussion of the current paper. Because the mathematical behavior is rather complex, the viscoelasticity involvement is reproduced only at the surface of separation, which is well-known as the viscous potential theory. Thereby, the equations of movement are scrutinized in a linear form, whereas a set of nonlinear boundary conditions are supposed. This procedure produces a nonlinear expressive nonlinear partial differential equation of the interface displacement. The non-perturbative approach which is based on the He’s frequency formula is employed to transform the nonlinear distinguishing ordinary differential equation with complex coefficients into a linear one. A novel process relying on the non-perturbative approach is utilized to examine the nonlinear stability and scrutinize the interface presentation. A non-dimensional analysis produces several dimensionless physical numerals. To validate the new approach, a comparison between the non-perturbative approach and its corresponding linear ordinary differential equation via the Mathematica Software is described and interpreted through a set of diagrams. Additionally, the Polar graphs have been elucidated. It is found that the mechanism of the stability does not change in the cases of real and complex coefficients.

The current analytical study is concerned with studying the impact of Cattaneo-Christov heat flux of an incompressible flow which obeys Carreau nanofluid inside a symmetric channel in the existence of the porous medium. The impacts of couple stress, heat generation absorption, joule heating, couple stress viscous dissipation with Soret as well as Dufour numbers are all presumed. Long wavelength and law Reynold’s number approximations are utilized for solving the governing system of equations. Furthermore, the traditional perturbation method together with the homotopy perturbation technique (HPM) are applied to obtain the resultant solutions of these equations. The different physical parameters on velocity, temperature and nanoparticles concentration distributions are illustrated through a set of graphs. It is found that the elevate in the slip velocity parameter dwindle the velocity. Meanwhile, the rise in the value of thermal relaxation time parameter led to decay the temperature of the fluid. Over and above, enhancing the nano Biot number value caused an enrichment in the concentration of nanofluid.

The current investigation described the influences of Cattaneo – Christov heat flux, Soret and Dufour, Hall current. The vertical alternating current produces an electric field is applied on the peristaltic flow of non - Newtonian micropolar nanofluid. The fluid flows inside a tapered stenosed artery. The non – Newtonian fluid obeys the tangent hyperbolic model. The effects of heat generation absorption, joule heating, thermal radiation, chemical reaction, and the permeability of the porous medium are imposed. The slip velocity and thermal slip conditions are assumed. The convective conditions for nanoparticles concentration as well as concentration are constructed. The coupled differential systems of equations yield Soret and Dufour feature. The assumption of the long wavelength with low Reynolds number is employed to simplify the governing equations of fluid motion to be ordinary differential equations. Furthermore, the obtained analytical solutions of these equations are based mainly on applying regular perturbation method together with homotopy perturbation method (HPM). The impacts of the various physical parameters on the axial velocity, spin velocity, temperature, nanoparticles concentration and concentration are illustrated and drawn graphically via a set of graphs. It is noticed that the velocity dwindled with an enriching in the magnitudes of both Hartman number, and electromagnetic parameter. Whereas, the axial velocity elevates with an enlargement in Darcy number, tapering angle, and Hall parameter. Moreover, the spin velocity declines with the increment in the microrotation parameter. Also, it is found that the escalating in thermal relaxation time causes a decaying impact on the temperature. Furthermore, enhancement in the nano Biot number leads to a declination in the magnitude of nanoparticles concentration. The current analytical study is very significant in several medical implementations, like the gastric juice motion in the small intestine when an endoscope is inserted through it.