TITLE:
Numerical Investigation of Magnetohydrodynamic (MHD) Natural Convection in a Nanofluid Filled Trapezoidal Cavity Considering the Use of Obstacle Shape, Wall Corrugation, and Inclination Angle
AUTHORS:
Sree Pradip Kumer Sarker, Md. Mahmud Alam
KEYWORDS:
MHD Natural Convection, Nanofluid Heat Transfer, Trapezoidal Enclosure, Wall Corrugation, Entropy Generation
JOURNAL NAME:
Applied Mathematics,
Vol.16 No.11,
November
11,
2025
ABSTRACT: This study presents a numerical investigation of magnetohydrodynamic (MHD) natural convection in a nanofluid-filled trapezoidal cavity, focusing on the combined effects of internal obstacle shape, wall corrugation, and inclination angle. Using Cu-H2O nanofluid and the finite element method, simulations were performed for Rayleigh numbers ranging from 103 to 106, Hartmann numbers from 0 to 50, and inclination angles of 15˚, 30˚, and 45˚. Results show that both obstacle geometry and wall corrugation profile strongly influence thermal performance. Square-shaped obstacles with triangular wavy walls achieved the highest Nusselt numbers, while sinusoidal walls provided superior thermodynamic efficiency, particularly at lower inclination angles. Increasing Hartmann numbers suppressed convective motion, as reflected by decreased Nu and ECOP values across all cases. The influence of geometric features, specifically obstacle shape and wall corrugation, was found to be most significant at low Rayleigh numbers, where buoyancy-driven flow is weaker and geometric modulation governs heat transport. The optimal configuration for enhanced heat transfer and energy efficiency was identified as square obstacles with sinusoidal or triangular walls at a 15˚ inclination and low Ha. These findings offer valuable guidance for designing thermally efficient enclosures in electronics cooling, solar collectors, and microfluidic systems, where controlling convection under magnetic effects is essential.