Natural convection of a viscoplastic fluid in an enclosure filled with solid obstacles

Numerical investigation of viscoplastic fluids on natural convection in open cavities with solid obstacles

“…The numerical investigation by Kefayati [ 39 ] aims to report the effects that the variation of parameters such as Bingham number ( Bn = 0–4), Rayleigh number ( Ra = 10 4 –10 6 ), Darcy number ( Da = 10 2 –10 6 ), porosity ( φ = 0.1–0.9), Lewis number ( Le = 2.5–100), Buoyancy ratio (N = 0.1–20) and Prandtl number (Pr = 1–100) have on heat and mass transfer. The results corroborate what is reported in closed cavities [ [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] ]; the heat transfer increases and the unyielded regions decrease with increasing Ra , Le and N.…”

“…Focusing on the effects of each geometry, the Prandtl number Pr and the fluid-solid thermal conductivity ratio κ were kept constant. s. It is important to note that the ratio of the thermal conductivity of the fluid used is ten times smaller than the thermal conductivity of the solid body ( ); this ratio represents a realistic order of magnitude for many possible solid materials, such as concrete, sandstone, and stainless steel [ 38 ]. As defined by Eq.…”

“…Authors such as Beverly and Tanner [ 43 ], Turan et al [ 44 ], and Santos et al [ 38 ] obtained good approximations using the biviscosity model for the relation μ B ≥ 10 3 μ p .…”

“…Especially viscoplastic fluids, which have the characteristic of deforming or flowing only when applied stresses are greater than a critical value known as the yield stress [ 30 ]. Different studies on closed cavities filled with Bingham fluid and inserted solid obstacles were found: cavity with a cylinder of different aspect ratios [ 31 , 32 ], two cylinders with different radius ratios and different positions [ [33] , [34] , [35] ], four cylinders with different radius ratio [ 36 ], a square block with different size ratios ( B = l / H ) [ 37 ] and with the number of blocks ranging from 4 to 64 [ 38 ]. However, only one study on natural convection in the open cavity with Bingham fluid [ 39 ] was found, without solid blocks inside the cavity.…”

Conjugate local thermal nonequilibrium and non‐Darcy flow inside porous enclosure: Analysis of localized heating and cooling arrangements

“…The findings indicated that the employing nanofluid guides to progress Nusselt number. While Santos et al 33 given the findings of free convective in a duct containing many hot square obstacles, Alturaihi et al 34 given the solutions of free convective in a cold duct containing circular obstacles and hot sheet set at the center of the duct and Javadzadegan et al 35 numerically examined convective heat transfer in a vented duct contains elliptical obstacles to confirm the impact of including porous medium on Nu . Subhash et al 36 focused on the free convection in a porous channel containing a couple of vertical diathermal partitions discrete at equal distance from the duct center.…”