Jianhong Liu¹, Dong Liu¹, Fumin Shang¹, Kai Yang¹, Xin Cao¹, Chaofan Zheng¹

Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería, Vol.40, No.2, pp. 1-7, 2024, DOI:10.23967/j.rimni.2024.05.005 - 22 May 2024

Abstract The Pulsating Heat Pipe (PHP), lauded for its efficacy in heat transfer, is distinguished by its uncomplicated architecture, economical production, diminutive form, and robust adaptability to environmental conditions. This study delineates the design of an asymmetric PHP heat transfer apparatus, achieved through the alteration of select conduit lengths within the comprehensive circulation system. The thermal transfer efficacy of this apparatus was empirically scrutinized under dual dissipation modalities: natural and forced convection. It was observed that the asymmetric PHP, when devoid of oscillatory activity, maintained a heat source temperature of 25∘C, whereas the temperature escalated to… More >

Amira M’hadbi^1,2,*, Mohammed El Ganaoui¹, Haïkel Ben Hamed³, Amenallah Guizani², Khalid Chtaibi³

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 2091-2108, 2024, DOI:10.32604/fdmp.2024.050763 - 23 August 2024

Abstract The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated numerically. In particular, the impact of nanofluids, composed of water and Al₂O₃, TiO₂, and Cu nanoparticles, on heat transfer enhancement is examined. The aim of this research is also to analyze the influence of different parameters, including the Rayleigh number (Ra = 10⁴ − 10⁶), nanoparticle volume fraction (φ = 0% − 20%), non-Newtonian power-law indexes (n = 0.6 − 1.4), and fin dimensions (Ar = 0.3, 0.5, and 0.7). Streamlines and isotherms are used to… More > Graphic Abstract

Junsong Xiong¹, Zhen Wang², Shaofan Li³, Xin Lai^1,*, Lisheng Liu^2,*, Xiang Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.1, pp. 151-169, 2024, DOI:10.32604/cmes.2024.053078 - 20 August 2024

Abstract Natural convection is a heat transfer mechanism driven by temperature or density differences, leading to fluid motion without external influence. It occurs in various natural and engineering phenomena, influencing heat transfer, climate, and fluid mixing in industrial processes. This work aims to use the Updated Lagrangian Particle Hydrodynamics (ULPH) theory to address natural convection problems. The Navier-Stokes equation is discretized using second-order nonlocal differential operators, allowing a direct solution of the Laplace operator for temperature in the energy equation. Various numerical simulations, including cases such as natural convection in square cavities and two concentric cylinders, More >

H. Benzzine, H. Labrim, Aouatif Saad^*, Y. Achour, D. Zejli, R. El Bouayadi

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.8, pp. 1903-1913, 2024, DOI:10.32604/fdmp.2024.050557 - 06 August 2024

Abstract This study addresses the pressing need for energy-efficient greenhouse management by focusing on the innovative application of natural ventilation. The primary objective of this study is to evaluate various ventilation strategies to enhance energy efficiency and optimize crop production in agricultural greenhouses. Employing advanced numerical simulation tools, the study conducts a comprehensive assessment of natural ventilation’s effectiveness under real-world conditions. The results underscore the crucial role of the stack effect and strategic window positioning in greenhouse cooling, providing valuable insights for greenhouse designers. Our findings shed light on the significant benefits of optimized ventilation and More > Graphic Abstract

Alexey Fedyushkin^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1351-1364, 2024, DOI:10.32604/fdmp.2024.050267 - 27 June 2024

Abstract This study is devoted to an analysis of natural convection and the emergence of delamination in an incompressible fluid encapsulated in a closed region heated from the side. Weak, medium and intensive modes of stationary laminar thermal and thermo-concentration convection are considered. It is shown that nonlinear flow features can radically change the flow structure and characteristics of heat and mass transfer. Moreover, the temperature and concentration segregation in the center of the square region display a non-monotonic dependence on the Grashof number (flow intensity). The formation of a nonstationary periodic structure of thermal convection More >

Dewi Puspitasari¹, Diah Kusuma Pratiwi¹, Pramadhony Amran², Kaprawi Sahim^1,*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 305-315, 2024, DOI:10.32604/fhmt.2023.041882 - 21 March 2024

Abstract The natural convection from a vertical hot plate with radiation and constant flux is studied numerically to know the velocity and temperature distribution characteristics over a vertical hot plate. The governing equations of the natural convection in two-dimension are solved with the implicit finite difference method, whereas the discretized equations are solved with the iterative relaxation method. The results show that the velocity and the temperature increase along the vertical wall. The influence of the radiation parameter in the boundary layer is significant in increasing the velocity and temperature profiles. The velocity profiles increase with More >

Afraz Hussain Majeed¹, Rashid Mahmood², Sayed M. Eldin³, Imran Saddique^4,5,*, S. Saleem⁶, Muhammad Jawad⁷

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1505-1519, 2024, DOI:10.32604/cmes.2023.030255 - 29 January 2024

Abstract This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin and magnetic field. The temperature is constant on the Y-shaped fin, insulating the top wall while the remaining walls remain cold. All walls are subject to impermeability and non-slip conditions. The mathematical modeling of the problem is demonstrated by the continuity, momentum, and energy equations incorporating the inclined magnetic field. For elucidating the flow characteristics Finite Element Method (FEM) is implemented using stable FE pair. A hybrid fine mesh is used for discretizing the domain. Velocity and More >

Noureddine Abouricha^1,*, Chouaib Ennawaoui^1,2, Mustapha El Alami³

Frontiers in Heat and Mass Transfer, Vol.21, pp. 523-537, 2023, DOI:10.32604/fhmt.2023.045914 - 30 November 2023

Abstract This work presents a simulation of the phenomena of natural convection in an enclosure with a variable heating regime by the lattice Boltzmann method (LBM). We consider a square enclosure of side H filled with air (Pr = 0.71) and heated from below, with a hot portion of length L = 0.8 H, by imposing a sinusoidal temperature. The unheated segments of the bottom wall are treated as adiabatic, and one of the vertical walls features a cold region, while the remaining walls remain adiabatic. The outcomes of the two-dimensional (2D) problem are depicted through isotherms, streamlines, More >

Muneerah Al Nuwairan^1,*, Elmiloud Chaabelasri²

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 133-154, 2023, DOI:10.32604/cmes.2022.022649 - 29 September 2022

Abstract In this paper, natural heat convection inside square and equilateral triangular cavities was studied using a meshless method based on collocation local radial basis function (RBF). The nanofluids used were Cu-water or -water mixture with nanoparticle volume fractions range of . A system of continuity, momentum, and energy partial differential equations was used in modeling the flow and temperature behavior of the fluids. Partial derivatives in the governing equations were approximated using the RBF method. The artificial compressibility model was implemented to overcome the pressure velocity coupling problem that occurs in such equations. The main goal… More > Graphic Abstract

Farah Zemani-Kaci^*, Amina Sabeur-Bendhina

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 513-539, 2023, DOI:10.32604/fdmp.2022.021974 - 29 August 2022

Abstract A two-dimensional numerical study of laminar natural convection in a square enclosure filled with air with a wall partially heated on the bottom is presented. The heat source is located on the lower wall with different heated widths varied from 20 to 80%(ε = 0.2–0.8) of the total width of the lower wall and different heights h = H/4 and H/2 of the partition. The effect of the partition height on the main system dynamics is investigated through solution of the two-dimensional Navier–Stokes equations and the energy equation by means of a finite volume method More > Graphic Abstract