Investigation of magnetohydrodynamic flow with tri-hybrid alumina-silica-copper-water nanofluids over a thin needle: impact of Arrhenius activation energy and thermal effects

This study investigates a steady magnetohydrodynamic flow involving a tri-hybrid nanofluid composed of aluminum oxide (\({\text{Al}}_{2} {\text{O}}_{3}\)), silicon dioxide (\({\text{SiO}}_{2}\)), and copper (\({\text{Cu}}\)) suspended in water. This flow occurs over a slender, thin needle subjected to a heat source or sink. We account for various complex phenomena, including viscous dissipation, Arrhenius activation energy, and the thermo-diffusion and diffusion-thermo effects, which influence thermal and convective mass transfer. To analyze this intricate system, we solve the modified governing equations using the bvp4c numerical tool, which addresses boundary value problems. This study shows that temperature profile grows with the Dufour and Eckert numbers; whereas, the concentration profile grows with the Soret number. Also, it demonstrates that elevating activation energy diminishes concentration profiles while enhancing thermal radiation boosts temperature profiles. As the nanoparticle volume fraction magnifies, fluid velocity declines, accompanied by a rise in temperature. Compared to water, introducing 1% of alumina oxide (\({\text{Al}}_{2} {\text{O}}_{3}\)), silicon dioxide (\({\text{SiO}}_{2}\)), and copper (\({\text{Cu}}\)) nanoparticles into the base fluid increases frictional drag by 1.01%, 0.37%, and 1.33%, respectively.