Role of various concave/convex walls exposed to solar heating on entropy generation during natural convection within porous right angled triangular enclosures

• Solar heating on concave or convex curved walls are done.
• Natural convection is studied for porous triangle with concave or convex hypotenuse.
• Studies are performed via entropy generation approach for various wall curvatures.
• The energy efficient case corresponds to the high heat transfer rate and low entropy generation rate.
• The energy efficient geometrical shape is chosen for various processing fluids.

The solar heating of the inclined wall has the direct application for the processing of various porous materials. Analysis of natural convection is carried out for the built structure where the right wall is exposed to the sun and the left wall is exposed to the cold ambience in the presence of the bottom adiabatic wall. The current work also involves with the study of the entropy generation for natural convection in porous right angled triangular enclosures with the concave/convex right wall. The finite element simulations are performed for a wide range of Darcy number (10-5⩽Dam⩽1010-5⩽Dam⩽10) at a representative high Rayleigh number (Ram=106Ram=106) for various fluids of industrial importance (Prm=7.2Prm=7.2: saline water, 0.7: air and 0.01: molten metal). An extensive investigation on the effect of DamDam for the entropy generation due to heat transfer (SθSθ) and fluid friction (SψSψ) is carried out for various cases of wall curvatures. In addition, the total entropy generation rate (StotalStotal), average Bejan number (BeavBeav) and average Nusselt number (Nul‾) are presented for various DamDam and PrmPrm. Overall, the built structure with the concave right wall (case 1) may be recommended for the thermal processing of fluids of all PrmPrm at all DamDam via the solar heating on the curved wall.