Ravi Shankar Prasad^a,*,†, Ujjwal Kumar Nayak^a, Rajen Kumar Nayak^a, Amit Kumar Gupta^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.4

Abstract This paper presents the results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the inversely linearly heated vertical opposite side walls and the adiabatic top and bottom walls. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., Navier-Stokes Equation in the stream function - vorticity form and Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For More >

Emad D. Aboud¹ , Qusay Rasheed Al-Amir², Hameed K. Hamzah², Ammar Abdulkadhim³, Mustafa M. Gabir³, Salwan Obaid Waheed Khafaji², Farooq H. Ali^2,*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-17, 2021, DOI:10.5098/hmt.17.19

Abstract The natural convection of nanofluid flow, which occurs between a sinusoidal-corrugated enclosure and a concentric inner cylinder has been numerically investigated. The two horizontal walls of this enclosure are considered adiabatic and two vertical corrugated walls are held at a constant value of the cold temperature while the inner concentric cylinder is heated isothermally. Different cylinder geometries (i.e, circular, square, rhombus, and triangular) located inside the enclosure are examined to find the best shape for optimum heat transfer. The physical and geometrical parameters influencing heat transfer are Rayleigh number (Ra=10³ -10⁶), undulation numbers (N=0,1 and 2),… More >

Quanfu Gao^a,b , Kun Zhang^a,b,*, Liang Bi Wang^a,b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-10, 2020, DOI:10.5098/hmt.14.29

Abstract Detailed numerical analysis is presented for natural convection heat transfer in internally finned horizontal annuli. Governing equations are discretized using the finite volume method, and solved using SIMPLE algorithm with Quick scheme. The results show that the flow and heat transfer can reach steady state when the Rayleigh number is below 2×10⁴. When the Rayleigh number is greater than 3×10⁴ , two different types of numerical solutions under the same parameters can be obtained for different initial conditions. The critical Rayleigh numbers with two different initial conditions are different from steady to unsteady solutions. The oscillatory More >

Hussein M. Jassim, Farooq H. Ali^* , Qusay R. Al-Amir, Hameed K. Hamzah, Salwan Obaid Waheed Khafaji

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.22

Abstract This study is focused on the entropy generation of laminar natural convection inside a sinusoidal enclosure filled with air (Pr=0.71). The numerical investigation is performed for three shapes of inner cylinders (circle, square, and equilateral triangle) with the same area and different values of the Rayleigh number (10³-10⁶). Galerkin Finite Element Approach is utilized to solve the governing equations. The results showed that the entropy generations due to heat transfer, fluid friction and total entropy generation increase with increasing values of Rayleigh number, while the local Bejan number decreases. More >

Hasan Sh. Majdi^a , Ammar Abdulkadhim^b,* , Azher M. Abed^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-14, 2019, DOI:10.5098/hmt.12.2

Abstract Fluid flow and natural convection heat transfer in a parallelogram enclosure with an inner circular cylinder using Cu-water nanofluid are studied numerically. Dimensionless Navier-Stokes and energy equations are solved numerically using finite element method based two-dimensional flow and steady-state conditions. This study evaluates the effect of different concentrations of Cu-water nanofluids (0% to 6%) with different Rayleigh numbers 10³ ≤ Ra ≤ 10⁶ under isotherm wall temperatures. The effects of geometrical parameters of the parallelogram enclosure (inclination angle in range of 0 ≤ α ≤ 30 and location of inner circular cylinder -0.2 ≤ H ≤… More >

Rafiq Manna^* , Patrick H. Oosthuizen

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-12, 2019, DOI:10.5098/hmt.13.7

Abstract Natural convective heat transfer from two-sided diagonally inclined square plates having various thicknesses has been numerically and experimentally investigated. The aim of this work is to determine the influence of the plate thickness and diagonal inclination angle on the heat transfer rate for various flow regimes. The mean heat transfer rate was numerically obtained using ANSYS FLUENT© and experimentally determined using the Lumped Capacity Method. The results indicate that the plate thickness does not have a significant influence on the heat transfer rate while the diagonal inclination angle significantly influences the heat transfer rate especially More >

Shantanu Dutta^* , Arup Kumar Biswas

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-12, 2018, DOI:10.5098/hmt.10.8

Abstract Industrial processes optimization for higher energy efficiency may be effectively carried out based on the thermodynamic approach of entropy generation minimization (EGM). This approach provides the key insights on how the available energy (exergy) is being destroyed during the process and the ways to minimize its destruction. In this study, EGM approach is implemented for the analysis of optimal thermal mixing and temperature uniformity due to natural convection in quadrantal cavity filled with porous medium for the material processing applications or for cooling of electrical equipments. Effect of the permeability of the porous medium and… More >

Mohammed A. Tashkandi^a , Abdelkarim Aydi^b,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-6, 2018, DOI:10.5098/hmt.11.27

Abstract In this work, a computational study of convective heat transfer in a hybrid CNT-Al2O3/water nanofluid cavity filled. The main considered parameters are the Rayleigh number and nanoparticles volume fraction. Results are presented in terms of flow structure, temperature field, and average Nusselt number. Since CNT and Al₂O₃ have different shapes to models are used to evaluate the effective thermal conductivity. It was found that both increasing Rayleigh number and nanoparticles volume fraction increase the heat transfer intensify the flow and affect the temperature field. Adding nanoparticles enhances the heat transfer due to the enhancement of the More >

M. Bouraoui^a, M. S. Rouabah^a, A. Abidi-Saad^b,c,d,*, A. Korichi^e, C. Popa^b , G. Polidori^b

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-6, 2017, DOI:10.5098/hmt.8.18

Abstract Study concerning a double skin flow with secondary ventilation was conducted numerically, in order to understand the basic mechanisms of the free convection in an open channel asymmetrically heated with uniform heat flux density (510 W/m² ). The vertical channel corresponds to a double skin façade, which was immersed in a tank filled with water. The tank corresponds to the environment which allows us to overcome pressure conditions at the inlet and the outlet of the channel. The use of water allows neglecting radiation effect. The mass conservation equations of momentum and energy are solved using More >

Nithish Reddy^* , K. Murugesan

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-11, 2017, DOI:10.5098/hmt.8.7

Abstract In this paper DDNC phenomenon in a bottom heated enclosure exposed to mass diffusion from its side walls is investigated numerically. The interplay between thermal and solutal buoyancy forces on fluid circulation and heat transfer rates is studied in three different enclosures of aspect ratios 0.5, 1.0 and 2.0. Finite element base numerical code has used to solve the governing equations, here velocity and vorticity are taken as primary variables for flow field. Numerical results are well validated with that of the literature. The relative strength of solutal to thermal buoyancy forces is defined by… More >