Forced Convection of Magnetohydrodynamic (MHD)-Boundary Layer Flow Past Thin Needle with Variable Wall Temperature Using Casson Nanofluid

The important goal in the twenty-first century has become to optimiz efficiency. For instance, heating, ventilation, and air conditioning (HVAC), an antifreeze or heat exchange fluid flows in a nuclear power reactor, heat-transfer design, etc. These advancements have been made either
 through the use of novel materials (duct walls with improved thermal insulation properties) comprising the duct walls, innovative geometric designs, or enhanced working fluids. In parallel with several additional areas of mechanical, medicinal, and energy engineering, nanotechnology has permeated
 duct design. Inspired by the remarkable potential of nanofluids, a subset of materials is created at the nanoscale. The study of thin needles in fluid flow is a very important aspect of biomedical areas and engineering industries. It is especially used in blood flow problems, circulatory problems,
 cancer therapy, aerodynamics, and fibre coating. In the current study, a novel mathematical model is created for the movement of the heat on a fine needle with changeable surface temperature using a Casson nanofluid. These governing equations are solved using the 4th order RK method and the
 collocation formula defined in bvp4c of Matlab software. To regulate the nanofluid, the Tiwari-Das model is used. The solid (metal) nanoparticles are added in the blood (carrier fluid). The momentum, energy, skin-friction coefficient, and Nusselt values are tabulated and displayed graphically.
 The Casson parameter raises the momentum but lowers the temperature. The Nusselt values are incremented when nanofluid is used instead of conventional fluids. For confined situations, numerical outcomes are compared with the literature and a good level of agreement is discovered.