Darcy-Forchheimer Hybrid Nanofluids Flow in Inner Extending and Outer Static Coaxial Cylinders for Thermal Applications

Abstract Hybrid nanofluids (HNFs) containing Al2O3 (Aluminum Oxide) and TiO2 (Titanium Dioxide) nanoparticles (NPs) are an emerging area of research with potential applications in many fields, such as heat transfer enhancement and medical treatments. These nanofluids exhibit unique properties that make them attractive for such applications, including enhanced thermal conductivity, antimicrobial properties, and biocompatibility. This pioneering study investigates the flow behavior of Al2O3 and TiO2 HNFs between the two coaxial cylinders including the stretching inner cylinder which is covered by the outer static cylinder such that the inside cylinder is heated and the external cylinder is cooled. The flow is driven by the stretching performance of the inner cylinder, and the curvature term between the two cylinders, and the heat transfer performance is evaluated based on the Nusselt number, which describes the effectiveness of heat transfer. The Darcy-Forchheimer medium is considered for the fluid flow in the existence of thermal radiations and viscous dissipation effects. The gap between the cylinders is varied to get different observations on the drag coefficient and heat transfer rate. The transformed set of nonlinear equations has been tackled through the homotopy analysis method (HAM). The curvature of the cylinders, gap parameters, Eckert number, radiation parameter, and nanoparticle volume fractions influence are observed. The % analysis to investigate the heat transfer enhancement also has been analyzed. The existing literature is recovered by exceeding the gap between the two cylinders to infinity.