Coupled magnetic-driven convection and radiative heat transfer in an inclined trapezoidal enclosure

Heatlines and masslines are two concepts utilized in fluid mechanics to visualize the flow of heat and mass in a fluid. This study numerically investigates magnetohydrodynamic (MHD) mixed convective heat and mass transmission in an inclined trapezoidal cavity occupied with an Al 2 O 3 -H 2 O nanofluid under the combined impact of internal heat source/sink and thermal radiative flux. Such configurations are important in the design of progressive thermal structures, including electronic cooling devices, energy storage units, and solar thermal collectors, where geometric inclination, magnetic control, and enhanced heat transfer fluids play a critical role. The governing non-dimensional conservation equations for momentum, temperature, and species concentration are resolved using a finite difference methodology coupled with the biconjugate gradient stabilized (BiCGStab) method. Transport phenomena are analyzed through streamlines, heatlines, and masslines, providing a detailed visualization of flow, heat, and mass pathways. The results reveal that improving the Richardson numbers from 0.01 to 10 significantly enhances buoyancy-driven convection, leading to an increase of up to 45 % in the average Nusselt numbers and 38 % in the Sherwood numbers. In contrast, raising the Hartmann number from 0 to 60 suppresses fluid movement because of the Lorentz force, lowering heat and mass transfer rates by nearly 30 %. An increment in nanoparticle volume fraction from 0 to 0.06 improves thermal transport, yielding approximately a 20 % enhancement in heat transfer despite a slight reduction in flow strength. Heat generation intensifies thermal gradients and compresses heatlines, resulting in a substantial increase in the Nusselt number, whereas heat absorption weakens convective transport. The inclination angle strongly alters flow symmetry and redistributes heatline and massline structures, indicating optimal orientations for enhanced transport. The innovation of this effort lies in the collective application of heatline and massline visualization to an inclined trapezoidal nanofluid cavity under simultaneous MHD and radiative heat generation/absorption effects, which has not been previously reported. Beyond conventional streamline-based analyses, this study offers new quantitative and physical insights into coupled thermo-solutal transport mechanisms, providing a more comprehensive outline for the design and optimization of complex MHD nanofluid thermal systems.