Thermal transport analysis for natural convection in a porous corrugated rhombic enclosure

Heat Transfer ◽  
2020 ◽  
Vol 49 (6) ◽  
pp. 3287-3313 ◽  
Author(s):  
Shantanu Dutta ◽  
Sukumar Pati ◽  
Arup Kumar Biswas
Keyword(s):  
Natural Convection ◽  
Thermal Transport ◽  
Transport Analysis

scholarly journals Natural convection of Bingham fluids in rectangular cross-sectional cylindrical annuli with differentially heated vertical walls

2019 ◽  
Vol 29 (1) ◽  
pp. 43-77 ◽  
Author(s):  
Sahin Yigit ◽  
Nilanjan Chakraborty
Keyword(s):  
Boundary Condition ◽  
Nusselt Number ◽  
Natural Convection ◽  
Yield Stress ◽  
Thermal Transport ◽  
Second Order ◽  
Bingham Fluids ◽  
Cross Sectional ◽  
Content Type ◽  
The Mean

PurposeThis paper aims to numerically analyse natural convection of yield stress fluids in rectangular cross-sectional cylindrical annular enclosures. The laminar steady-state simulations have been conducted for a range of different values of normalised internal radius (ri/L1/8 to 16, whereLis the difference between outer and inner radii); aspect ratio (AR=H/Lfrom 1/8 to 8 whereHis the enclosure height); and nominal Rayleigh number (Rafrom 103to 106) for a single representative value of Prandtl number (Pris 500).Design/methodology/approachThe Bingham model has been used to mimic the yield stress fluid motion, and numerical simulations have been conducted for both constant wall temperature (CWT) and constant wall heat flux (CWHF) boundary conditions for the vertical side walls. The conservation equations of mass, momentum and energy have been solved in a coupled manner using the finite volume method where a second-order central differencing scheme is used for the diffusive terms and a second-order up-wind scheme is used for the convective terms. The well-known semi-implicit method for pressure-linked equations algorithm is used for the coupling of the pressure and velocity.FindingsIt is found that the mean Nusselt number based on the inner peripheryNu¯iincreases (decreases) with an increase inRa(Bn) due to augmented buoyancy (viscous) forces irrespective of the boundary condition. The ratio of convective to diffusive thermal transport increases with increasingri/Lfor both Newtonian (i.e.Bn= 0) and Bingham fluids regardless of the boundary condition. Moreover, the mean Nusselt numberNu¯inormalised by the corresponding Nusselt number due to pure conductive transport (i.e.Nu¯i/(Nu¯i)cond) shows a non-monotonic trend with increasingARin the CWT configuration for a given set of values ofRa,Pr,Lifor both Newtonian (i.e.Bn= 0) and Bingham fluids, whereasNu¯i/(Nu¯i)condincreases monotonically with increasingARin the CWHF configuration. The influences of convective thermal transport strengthen while thermal diffusive transport weakens with increasingAR, and these competing effects are responsible for the non-monotonicNu¯i/(Nu¯i)condvariation withARin the CWT configuration.Originality/valueDetailed scaling analysis is utilised to explain the observed influences ofRa,BN,ri/LandAR, which along with the simulation data has been used to propose correlations forNu¯i.

scholarly journals Biomimetic Bacterial Identification Platform Based on Thermal Transport Analysis Through Surface Imprinted Polymers: From Proof of Principle to Proof of Application

2019 ◽  
Vol 216 (12) ◽  
pp. 1800688 ◽  
Author(s):  
Benjamin Heidt ◽  
Renato Rogosic ◽  
Joseph W. Lowdon ◽  
Muriel Desmond‐Kennedy ◽  
Kaste Jurgaityte ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Bacterial Identification ◽  
Imprinted Polymers ◽  
Transport Analysis ◽  
Proof Of Principle

Graphene grain size-dependent synthesis of single-crystalline Sb2Te3 nanoplates and the interfacial thermal transport analysis by Raman thermometry

Carbon ◽  
2019 ◽  
Vol 153 ◽  
pp. 164-172 ◽  
Author(s):  
Swati Singh ◽  
Seongkyun Kim ◽  
Wonjae Jeon ◽  
Krishna P. Dhakal ◽  
Jeongyong Kim ◽  
...  
Keyword(s):  
Grain Size ◽  
Thermal Transport ◽  
Single Crystalline ◽  
Size Dependent ◽  
Transport Analysis
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