Triple mass diffusion phenomenon in tangent hyperbolic fluid with variable thickness, Soret, and Dufour theory: Galerkin finite element method

This study’s objective focuses on the transport phenomena of triple mass diffusion for the steady and incompressible flow of hyperbolic tangent fluid on a vertical surface including variable thickness, solutal buoyancy, and thermal forces. The governing equations contain momentum, continuity, heat, non-Newtonian influences, and species transport equations considering triple diffusion. The heat transfer mechanism is discussed with the effects of heat sink/source, thermal, and mass diffusion. It is noticed that the properties of the variable fluid are observed, including concentration- and temperature-dependent influences. A similarity transformation converts partial differential equations (PDEs) to ordinary differential equation (ODEs). Such a complex problem is simulated using a finite element approach while considering a variable thickness surface. Including results exhibits insights into the influence of chemical species, thermophoretic forces, and buoyancy-induced convection on mass and heat transfer mechanisms. It is included that the velocity fields are decreasing function with increments of We, NR, and m but increasing function vs velocity fields and buoyancy ratios for salt 1 and 2 are investigated. Heat energy is boosted up with increments of the heat sink, Dufour, and Dufour solute Lewis for salts 1 and 2. When the Weissenberg number and power-law index are enhanced, the skin friction coefficient is declined. Shear-thinning effects are lessened by a higher power-law index, which results in smaller velocity gradients close to the wall and lower shear stress.