Entropy generation on MHD flow of second-grade hybrid nanofluid flow over a converging/diverging channel: an application in hyperthermia therapeutic aspects

This study's primary objective is to investigate the Jeffery-Hamel model and entropy generation on the Magnetohydrodynamic (MHD) flow of second-grade hybrid nanofluid across stretchable converging and diverging channels. Silver (Ag) and ferroferric oxide (Fe3O4) are nanoparticles, using blood as the base fluid. The controlling nonlinear coupled Partial Differential Equations (PDEs) are transformed into Ordinary Differential Equations (ODEs) with similarity transformations and then solved using the Homotopy Perturbation Method (HPM) and shooting technique (Runge-Kutta fourth order) in the MAPLE software. The Homotopy Perturbation Method (HPM) is compared to the Numerical Method (NM), and the results are more accurate and reliable. The effects of velocity, temperature, entropy production, and the Bejan number on physical parameters like a magnetic field, Reynolds number, magnetic field, porosity, and the Brinkman number are discussed through graphs and tables. The heat transfer and skin friction coefficients are also studied and portrayed as graphs. The velocity profile increases for second-grade hybrid nanofluid across stretchable converging and diverging channels as the magnetic field parameter increase. The velocity profile decreases as Deborah's number increases for the converging channel. As Deborah's number increases, the velocity profile increases for the diverging channels. The magnetic field and volume fraction increase as the skin friction and Nusselt number increase for second-grade hybrid nanofluid across stretchable converging and diverging channels. This theoretical model, which incorporates MHD with blood flow, is essential for biomedical applications, magnetic resonance imaging (MRI), particularly radiofrequency ablation (RFA), tumour treatment, and cancer therapy.