Analysis of thermal efficiency via analysis of heat flow and entropy generation during natural convection within porous trapezoidal cavities

Numerical analysis of natural convection in a triangular cavity with different configurations of hot wall

“…This augmentation in the buoyancy force establishes a strong regime of convection heat transfer inside the cavity which leads to the enhancement of the average Nusselt number. For triangular heating, at Ra = 1x10 5 , the average Nusselt number, Nu, is 5.04%, 11.1% and 17.3% for σ = 0.05, σ = 0.1 and σ = 0.15 respectively more than smooth heating. Furthermore, at Ra = 1x10 7 , the average Nusselt number, Nu, is 2.65%, 4.85% and 6.76% for σ = 0.05, σ = 0.1 and σ = 0.15 respectively more than smooth heating.…”

“…A strong buoyancy force is being buildup inside the cavity with the increment in the temperature gradient and hence the flow pattern of the fluid is changed significantly. From streamlines, it is observed that the two vortexes at Ra = 1x10 5 , three at Ra = 5x10 5 and 1x10 6 and four vortexes are formed at Ra = 5x10 6 and 1x10 7 . At low Rayleigh number, the smaller temperature gradient is unable to setup a strong buoyancy force and thus the heat carrying capacity by the fluid particles is less.…”

“…The above governing equations (1)(2)(3)(4)(5) in conjunction with the corresponding boundary conditions (6) are discretized using finite volume method which available in commercially software FLUENT 6.3 [26]. The SIMPLE algorithm and second order upwind technique are espoused for pressure velocity coupling and for convection and diffusion terms in momentum and energy equations respectively.…”

“…Ample literatures are available on various geometrical shaped enclosures such as square, rectangular, trapezoidal, quadrantal etc. heated or cooled from the enclosure walls [1][2][3][4][5][6][7]. Heat transfer analysis in triangular enclosures heating from side or below are substantially employed in various domestics and industrial applications [8][9][10][11].…”

Natural Convection and Entropy Generation in Nanofluid Filled Entrapped Trapezoidal Cavities under the Influence of Magnetic Field

“…MHD convection with nanofluids related to entropy generation and second law analysis were studied by several researchers [43][44][45][46]. Thermal management of free convection within trapezoidal cavities with distributions of heatlines and entropy generation by using the Galerkin finite element method was investigated in reference [47]. Optimal tilt angles of the square cavity were found in a tilted porous cavity with natural convection effect based on minimum entropy generation.…”