Dynamics of thermosolutal Marangoni convection and nanoparticle aggregation effects on Oldroyd-B nanofluid past a porous boundary with homogeneous-heterogeneous catalytic reactions

Entropy production with the flow of nanomaterials through the permeable stretched surface with heterogeneous-homogenous chemical reaction

In various thermodynamic procedures and the optimisation of thermal manipulation, nanofluids flowing through porous media represent an emerging perspective. The main objective of this study, from the perspective of thermal applications, was the investigation of the flow of nanofluid over a horizontal stretched surface embedded in a porous medium. The effects of the chemical reactions on the surface, magnetic field, and thermal radiations were invoked in the mathematical formulation. The non-Darcy model examines the fluid flow in the porous media. The principles of thermodynamics were employed to integrate entropy optimisation methods with the established theoretical approach to analyse the thermal behaviour of nanomaterials in the chemical reactive diffusion processes. Using the Tiwari-Das nanofluid model, the volume fraction of the nanomaterials was merged in the mathematical equation for the flow model. Water was taken as a base fluid and nanoparticles composed of aluminium oxide (Al2O3) and silver (Ag) were used. The significance of radiation, heat production, and ohmic heating were included in the energy equation. Furthermore, an innovative mathematical model for the diffusion of the autocatalytic reactive species in the boundary layer flow was developed for a linear horizontally stretched surface embedded in a homogeneous non-Darcy porous medium saturated with the nanofluid. The computer-based built-in bvp5c method was used to compute numerically these equations for varied parameters. It is clear that the magnetic parameter has a reversal influence on the entropy rate and velocity. Temperature and velocity are affected in the opposite direction from a higher volume fraction estimate. Thermal field and entropy were increased when the radiation action intensified. The inclusion of nanoparticle fraction by the volume fraction of nanoparticles and Brinkman number also enhances the system entropy. Entropy production can be minimized with the involvement of the porosity factor within the surface.

Significance of improved heat conduction on unsteady axisymmetric flow of Maxwell fluid with cubic autocatalysis chemical reaction

This paper investigates the effect of chemical reactions on the flow of magnetized Maxwell fluid generated by an unsteady stretching surface. The thermal transport phenomenon is analyzed by using the Cattaneo-Christov theory. By applying the appropriate similarity transformations, the governing equations of motion turn into a set of nonlinear differential equations. For the velocity, temperature, and concentration fields, the resultant equations are then solved as series solutions using the homotopy analysis approach. Using graphical representations, the physical behavior of significant factors is examined in depth. The analysis reveals that higher Maxwell parameter values reduce the flow field while increasing energy transportation in the fluid flow. Further, it is noted that thermal distribution declines for the higher values of the thermal relaxation parameter. Additionally, the solutal distribution bootup for the increasing values of Schmidt number while it shows a decreasing trend for homogeneous and heterogeneous reactions strength. In order to verify our findings, a comparison to earlier research is also included.

Darcy-Forchheimer Magnetized Nanofluid flow along with Heating and Dissipation Effects over a Shrinking Exponential Sheet with Stability Analysis

Nanoparticles have presented various hurdles to the scientific community during the past decade. The nanoparticles dispersed in diverse base fluids can alter the properties of fluid flow and heat transmission. In the current examination, a mathematical model for the 2D magnetohydrodynamic (MHD) Darcy-Forchheimer nanofluid flow across an exponentially contracting sheet is presented. In this mathematical model, the effects of viscous dissipation, joule heating, first-order velocity, and thermal slip conditions are also examined. Using similarity transformations, a system of partial differential equations (PDEs) is converted into a set of ordinary differential equations (ODEs). The problem is quantitatively solved using the three-step Lobatto-three formula. This research studied the effects of the dimensionlessness, magnetic field, ratio of rates, porosity, Eckert number, Prandtl number, and coefficient of inertia characteristics on fluid flow. Multiple solutions were observed. In the first solution, the increased magnetic field, porosity parameter, slip effect, and volume percentage of the copper parameters reduce the velocity field along the η-direction. In the second solution, the magnetic field, porosity parameter, slip effect, and volume percentage of the copper parameters increase the η-direction velocity field. For engineering purposes, the graphs show the impacts of factors on the Nusselt number and skin friction. Finally, the stability analysis was performed to determine which solution was the more stable of the two.