Saad Adjal^1,*, Sabiha Aklouche-Benouaguef¹, Belkacem Zeghmati²

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1389-1397, 2022, DOI:10.32604/fdmp.2022.021619 - 27 May 2022

Abstract Two-dimensional transient laminar natural convection in a square cavity containing a porous medium and inclined at an angle of 30∘ is investigated numerically. The vertical walls are differentially heated, and the horizontal walls are adiabatic. The effect of Rayleigh number on heat transfer and on the road to chaos is analyzed. The natural heat transfer and the Darcy Brinkman equations are solved by using a finite volume method and a Tri Diagonal Matrix Algorithm (TDMA). The results are obtained for a porosity equal to 0.45, a Darcy number and a Prandtl respectively equal to 10⁻³ and More >

Dolat Khan¹, Gohar Ali¹, Arshad Khan², Ilyas Khan^3,*

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 1025-1034, 2022, DOI:10.32604/cmc.2022.012635 - 03 November 2021

Abstract The basic objective of this work is to study the heat transfer of Casson fluid of non-Newtonian nature. The fluid is considered over a vertical plate such that the plate exhibits arbitrary wall shear stress at the boundary. Heat transfers due to exponential plate heating and natural convection are due to buoyancy force. Magnetohydrodynamic (MHD) analysis in the occurrence of a uniform magnetic field is also considered. The medium over the plate is porous and hence Darcy’s law is applied. The governing equations are established for the velocity and temperature fields by the usual Boussinesq… 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 >

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b , Olawale S. Ismail^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-8, 2021, DOI:10.5098/hmt.17.11

Abstract The problem of natural convection in rectangular cavities with different aspect ratios has been numerically analyzed in this study. Cavities considered have their right vertical walls heated and cooled at the opposite with constant temperatures, while horizontal walls are kept adiabatic. The objective of this study is to ascertain the significant effects of Rayleigh numbers (Ra), Nusselt numbers (Nu) and aspect ratios (AR) on flow and heat transfer in rectangular cavities. The equations of Navier-Stokes and energy are solved by applying Galerkin weighted residual Finite Element Method. Parametric calculations are performed for Rayleigh numbers (Ra)… More >

Zehba A. S. Raizah¹, Abdelraheem M. Aly^1,2,*

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3233-3251, 2021, DOI:10.32604/cmc.2021.012402 - 28 December 2020

Abstract This study simulates natural convection flow resulting from heat partitions in an H-shaped enclosure filled with a nanofluid using an incompressible smoothed particle hydrodynamics (ISPH) method. The right area of the H-shaped enclosure is saturated with non-Darcy porous media. The center variable partitions of the H-shaped enclosure walls are kept at a high-temperature T_h. The left and right walls of the H-shaped enclosure are positioned at a low temperature T_c and the other walls are adiabatic. In ISPH method, the source term in pressure Poisson equation (PPE) is modified. The influences of the controlling parameters on… 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 >

Zhiyun Wang^† , Zixuan Zhou, Mo Yang

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-7, 2020, DOI:10.5098/hmt.14.13

Abstract Double diffusive natural convection in an open cavity under the Soret and Dufour effect is simulated numerically. The influences of different Rayleigh numbers (range from 103 to 107), Lewis numbers (range from 0.5 to 8), buoyancy ratios (range from -5 to 5) and Soret and Dufour (range from 0 to 0.5) on the flow field, temperature and concentration distributions, as well as on the variation of the average Nusselt number and the average Sherwood number are investigated. The result shows that, when buoyancy ratios is -1, the average Nusselt number and the average Sherwood number… More >

Mahmud H. Ali^a,* , Rawand E. Jalal^a

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-14, 2020, DOI:10.5098/hmt.15.27

Abstract In this work, natural convection in an adiabatic enclosure with openings induced by two isothermal hot cylinders is approached numerically. The study covers five different configurations of the enclosure as the number and locations of the inlet and outlet ports are varied for Rayleigh number (Ra) between 10⁴ and 10⁶ . Additionally, the study also analyzes the effects of varying the horizontal distance (S) between the cylinders along with their vertical locations () for dimensionless values of 0.4 to 0.3 and -0.2 to 0.2, respectively, at a constant Ra of 10⁶ . The outcomes show that the… More >

Latifa M. Al-Balushi, M. M. Rahman^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 441-463, 2020, DOI:10.32604/fdmp.2020.08551 - 25 May 2020

Abstract In the present paper, the effect of the heat flux distribution on the natural convective flow inside a square cavity in the presence of a sloping magnetic field and magnetic nanoparticles is explored numerically. The nondimensional governing equations are solved in the framework of a finite element method implemented using the Galerkin approach. The role played by numerous model parameters in influencing the emerging thermal and concentration fields is examined; among them are: the location of the heat source and its lengthH*, the magnitude of the thermal Rayleigh number, the nanoparticles shape and volume fraction, and… More >

Suvash C. Saha^1,*, Ali M. Sefidan², Atta Sojoudi³

Energy Engineering, Vol.117, No.1, pp. 1-17, 2020, DOI:10.32604/EE.2020.010418 - 28 February 2020

Abstract Free convection inside an attic enclosure in which sinusoidal heat flux applied on the inclined walls and a constant temperature applied on the base wall has been investigated numerically to demonstrate the primary flow characteristics and heat transfer within the attic enclosure over daily routine cycles. To solve the governing equations, the finite volume technique has been utilized. After performing the grid independency and time step size tests, the roles of Rayleigh number (Ra) and the attic aspect ratio (AR) on the unsteady flow structure and heat transfer phenomenon are explained for a constant Prandtl More >