Significance of Riga Plate on Marangoni Convective Flow of Casson Hybrid Nanofluid over a Stretching/Shrinking Sheet with Suction and Darcy-Forchheimer Effects

This study investigates the heat transfer and Marangoni convection flow of a hybrid Al$_2$O$_3$-Cu/water nanofluid over a stretching/shrinking sheet. Surface tension-driven thermal Marangoni convection arises from the wall temperature gradient. The novel aspects include the combined effects of a Riga plate, thermal radiation, the Darcy--Forchheimer model, and Casson fluid characteristics. The Riga plate, comprising magnets and electrodes, generates a Lorentz force influenced by the fluid's vertical electrical conductivity. Similarity transformations convert the governing partial differential equations into ordinary differential equations, which are numerically solved using MATLAB's bvp4c solver. Results show that increasing the Marangoni convection and surface movement parameters enhances the velocity profile while reducing the temperature distribution. Conversely, higher porous medium and Casson parameters decrease both velocity and temperature profiles. The suction parameter reduces the velocity profile while significantly enhancing the Nusselt number by thinning the thermal boundary layer. Streamline and isotherm plots are presented for various parameters. Additionally, the skin friction coefficient and Nusselt number are discussed. These findings hold promise for industrial and medical applications, including biomedical device design, targeted drug delivery, and wastewater treatment.