Analysis of thermal characteristics of graphene-water nanofluid flow between coaxially rotating squeezing disks using HPM-Padé technique

Abstract Heat transfer enhancement and flow characteristics of graphene-water nanofluid are investigated with a semi-analytic solution framework for coaxially rotating squeezing disks, giving particular emphasis on thermal transport mechanisms governing the squeeze-flow dynamics. This paper primarily focuses on how squeezing intensity and nanoparticle concentration drive heat transfer behavior in this configuration. A similarity transformation is employed to reduce the governing partial differential equations to a system of nonlinear ordinary differential equations. The nonlinear system is solved using the homotopy perturbation method combined with Padé approximants to extend the convergence of the resulting series solutions, thereby extending the applicability of the semi-analytical solutions to physically relevant parameter regimes. The solutions are validated against existing literature for a limiting case and compared with numerical solutions from bvp5c across the investigated parameter ranges, showing excellent agreement. The effects of squeezing, rotation, and nanoparticle volume fraction are examined, revealing squeezing intensity and graphene concentration as the dominant influences on Nusselt number and skin friction coefficient, while rotation of the two disks has a very small effect on heat transfer process.