Akademik Veri Yönetim Sistemi
CASE STUDIES IN THERMAL ENGINEERING, cilt.81, 2026 (SCI-Expanded, Scopus)
This study presents a comprehensive numerical investigation into laminar natural convection within a porous square enclosure, focusing on the intricate interplay between buoyancy forces and porous matrix permeability. Simulations were executed across a broad parameter space, encompassing Rayleigh numbers from 103 to 106 and Darcy numbers ranging from 10-1 to 10-5, while systematically varying the linear heating position HS along the left vertical boundary. The thermal and hydrodynamic behavior was characterized using streamline, isotherm, and heatline visualizations, complemented by a rigorous second-law analysis involving entropy generation components and the Bejan number. A primary finding indicates that permeability serves as a more decisive factor in modulating heat transfer rates than the Rayleigh number, with increased porous resistance significantly suppressing flow velocities. Thermodynamic optimization, evaluated through the Energy Coefficient of Performance (ECOP), identified the uppermost heating configuration (HS = 1) as the most efficient regime, yielding maximized heat transfer alongside minimized irreversibility. Conversely, the highest thermodynamic losses were observed at HS = 0.25. The results further reveal that in low-permeability regimes (Da = 10-5), the total entropy production is almost entirely dominated by thermal gradients, whereas the sensitivity of the ECOP to heating positions diminishes at higher Rayleigh numbers.