Analysis of heat transfer models of electromagnetohy-drodynamic potassium dichromate (K2Cr2O7) nanofluid flow past through the cylindrical coordinate

This study presents a theoretical analysis of electromagnetohydrodynamic (EMHD) heat transfer in potassium dichromate (K2Cr2O7) nanofluid flow formulated in cylindrical coordinates. The model accounts for the combined influence of electric and magnetic fields, nanoparticle volume fraction, thermal radiation, and viscous dissipation effects on the momentum and thermal boundary layers. The governing nonlinear partial differential equations describing the flow and temperature fields are transformed into a coupled system of nonlinear ordinary differential equations through suitable similarity transformations. To obtain accurate approximate analytical solutions, the Homotopy Perturbation Method (HPM) is employed, providing rapidly convergent series expressions for the velocity and temperature distributions. The effects of key dimensionless parameters, including the magnetic interaction parameter, electric field parameter, Prandtl number, radiation parameter, and nanoparticle concentration, are investigated in detail. The results indicate that an increase in the magnetic parameter significantly reduces the velocity profile due to Lorentz force resistance, whereas a stronger electric field intensity enhances the acceleration of the flow. Furthermore, increasing the nanoparticle volume fraction improves the effective thermal conductivity, leading to a noticeable enhancement in the surface heat transfer rate and Nusselt number. Thermal radiation is found to elevate the temperature distribution and increase the thickness of the thermal boundary layer. Overall, the EMHD mechanism provides an efficient means of controlling heat transfer in cylindrical nanofluid transport systems. The outcomes of this work are relevant to the design of advanced electromagnetic thermal management devices, energy conversion systems, and nanofluid-based cooling technologies.