Computational study of radiative magnetohydrodynamic non-Newtonian MgO-TiO 2 -CH 3 OH hybrid nanofluid transport from a stretching substrate: Nano-cosmetic manufacturing simulation

Nano-powders have revolutionized the beauty and cosmetic industry, introducing groundbreaking innovations in product formulation and skin protection. Cutting-edge cosmetology leverages titania nanopowders to enhance pigmentation and luminosity in various beauty products, including eye shadows, lipsticks, balms, and lotions. These nanoscale particles not only amplify esthetic qualities but also provide advanced functional benefits including improved hydration, durability, facial radiance, and anti-wrinkling characteristics. Furthermore, magnetic nanoparticles have also shown enhanced tunability in emerging cosmetic applications. The intersection of scientific research and cosmetic technology has led to fascinating developments in nanofluid dynamics. Motivated by the manufacturing fluid dynamics of nano-cosmetics, in the present work we investigate the non-Newtonian magnetohydrodynamic (MHD) titania-magnesium oxide/methanol (wood spirit) cosmetic nanoliquid dynamics from a stretching surface with a power-law velocity. The Casson viscoplastic model is deployed for rheological effects. Convective and radiative heat transfer are included in the transport model as are viscous heating, internal heat source and wall transpiration (suction/injection) effects. A Tiwari-Das volume fraction formulation is adopted for nanofluid properties. The primitive conservation equations with associated boundary conditions are transformed into a nonlinear coupled ordinary differential boundary value problem which is solved computationally with the Runge-Kutta Fehlberg technique. Validation with previous studies ignoring nanoparticles is included. The innovative hybrid nanoflow composition, combining MgO and TiO₂, demonstrates remarkable potential in both cosmetic and industrial applications. When suspended in non-Newtonian cosmetic creams and exposed to sunlight, the hybrid nanoparticles lead to improved heat transfer properties of hybrid nanofluid suspensions. Notably, they can help mitigate skin tanning during exposure to intense solar radiation, by effectively managing thermal radiation and energy transmission to the skin’s surface. Hybrid nanofluids are observed to transfer more energy away from the stretchable surface when internal viscous dissipation and heat generation are present. The optically thin nano-cosmetic fluids simulated using the Rosseland flux model exhibit a decrease in energy transmission rate. Computations also show that as wall suction or injection escalates, skin friction decreases. Overall enhanced thermal management in cosmetic formulations is produced with MgO and TiO₂ hybrid nanoparticles relative to only unitary MgO nanoparticles.