Numerical analysis for MHD Fe₃O₄ -Cu/blood hybrid nanofluid flow in a disk-cone geometry: Application of biomedical...

The transfer of heat in hybrid nanofluid flow with blood as the base fluid between a disk and a cone holds considerable engineering importance because of its applications in medical devices, thermal power systems and rotating machinery, where effective heat removal is vital for improving performance, reliability, and energy efficiency. Therefore, the current investigation concerns a hybrid nanofluid consisting of blood as the carrier fluid, with copper (Cu) and magnetic ferrite (Fe₃O₄) nanoparticles dispersed throughout the blood under the influence of thermal radiation and a magnetic field. For the base fluid, the non-Newtonian Casson fluid model is employed to represent blood. The influence of the heat source/sink is also considered. The whole study is based on the boundary layer approximation.

The governing equations are derived using a cylindrical coordinate system. These equations are highly non-linear PDE's. Similarity transformations are used to transform a system of PDEs to ODEs. The governing transport equations are complicated, making it challenging to discover analytical solutions. The NDSolve technique is used to find the numerical solution of these non-dimensionalised rheological equations via Mathematica Software 11.0. Moreover, the comparison between the nanofluid and the hybrid fluid is discussed. Four distinct rotational cases are discussed: a) the cone is at a stationary state, and the disk is rotating; b) the disk is at a stationary state, and the cone is rotating; c) both the disk and cone are rotating in the same direction; and d) both the disk and cone are rotating in the opposite direction.

A detailed examination of the physical behavior of embedded parameters on flow features is shown via the graphical representations. It is noticed that the thermal energy and fluid motion are enhanced with the increment of the nanoparticle concentration in the base fluid. Furthermore, the magnitudes of both the velocity profile and temperature distribution are reduced by increasing magnetic effects.

These results can be used to control the motions of blood based NF or HNF in viscometer and thermal management applications because these configurations resemble the cone-disk geometry. Additionally, they can be applied in narrow-gap rotating devices and rotating cone-disk rheometers.