Cong Qi^1,2,*, Chengchao Wang^1,2, Jinghua Tang^1,2, Dongtai Han²

Energy Engineering, Vol.117, No.2, pp. 63-78, 2020, DOI:10.32604/EE.2020.010433

Abstract Because of the poor thermal performance of ordinary tubes, a triangular tube was used to replace the smooth channel in the heat transfer system, and nanofluids were used to take the place of ordinary fluids as the heat transfer medium. High stability nanofluids were prepared, and an experimental set on flow and heat exchange was established. Effects of triangular tube rotation angles (α = 0°, 30°, 60°) as well as mass fractions of nanofluids (ω = 0.1%, 0.3%, 0.5%) on heat exchange and flow performance were experimentally considered at Reynolds numbers (Re = 800–8000). It was shown that the triangular… More >

Yongtong Li¹, Liang Gong^{1, *}, Hui Lu¹, Dexin Zhang¹, Bin Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 895-912, 2020, DOI:10.32604/cmes.2020.09009

Abstract In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers predicted by both the LTE… More >

J. Serrano-Arellano¹, J. M. Belman-Flores^2,*, I. Hernández-Pérez³, K. M. Aguilar-Castro³, E. V. Macías-Melo³, F. Elizalde-Blancas², J. M. Riesco-Ávila², F. J. García-Rodríguez⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 571-602, 2020, DOI:10.32604/cmes.2020.08677

Abstract In the present study, an analysis of the heat and mass transfer in a ventilated cavity in a warm climate zone was carried out to analyze, among others, the temperatures and percentage of relative humidity (RH). The governing equations of the mathematical model were solved through the finite volume method. We used the k-ε turbulence mode to find the results of the variables of interest in seven climate records on a given day. The velocity of the inlet flow of the air-H₂O mixture was varied through the Reynolds number (Re) from 500 to 10000. The outdoor weather conditions considered were… More >

Yuanliang Tang^{1, 2}, Lizhong Mu¹, Ying He^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 281-296, 2020, DOI:10.32604/fdmp.2020.06760

Abstract The aim of this study is to develop a model of fluid and heat transfer in a biological tissue taking into account the exact structure of the related microvascular network, and to analyze the influence of structural changes of such a network induced by diabetes. A cubic region representing local skin tissue is selected as the computational domain, which in turn includes two intravascular and extravascular sub-domains. To save computational resources, the capillary network is reduced to a 1D pipeline model and embedded into the extravascular region. On the basis of the immersed boundary method (IBM) strategy, fluid and heat… More >

Lionel Fabian Fourie¹, Lynndle Square^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 225-235, 2020, DOI:10.32604/fdmp.2020.08771

Abstract A heat transfer study was conducted, in the framework of Computational Fluid Dynamics (CFD), on a Hot-Wire Chemical Vapour Deposition (HWCVD) reactor chamber to determine a safe deposition distance for atomic hydrogen produced by HWCVD. The objective of this study was to show the feasibility of using heat transfer simulations in determining a safe deposition distance for deposition of this kind. All CFD simulations were set-up and solved within the framework of the CFD packages of OpenFOAM namely; snappyHexMesh for mesh generation, buoyantSimpleFoam and rhoSimpleFoam as the solvers and paraView as the post-processing tool. Using a standard set of deposition… More >

Mounir Kriraa^1,2,*, Khalid Souhar³, Driss Achemlal⁴, Youssef Ait Yassine^5,6, Abdelmajid Farchi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 199-209, 2020, DOI:10.32604/fdmp.2020.07986

Abstract In this paper, a detailed investigation of water (Pr ¼ 7:0) convection in a chemical condenser is carried out. Two openings are located along one side of the cavity. The Navier-Stokes equations are solved in the frame of a control volume method using the SIMPLEC algorithm to implement adequate coupling of pressure and velocity. Special emphasis is given to the influence of the Reynolds number, the tilt of the channel and the Rayleigh number on the convective heat transfer. Results are presented and discussed allowing the control parameters to span relatively wide intervals: Rayleigh number (10⁴ ≤ Ra ≤ 5… More >

Houda Jalali^{1, ∗}, Hassan Abbassi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 181-198, 2020, DOI:10.32604/fdmp.2020.07804

Abstract The addition of nanoparticles into liquid, even at low concentrations, leads to an increase in both, dynamic viscosity and thermal conductivity. Furthermore, the increase in temperature causes an increase in thermal conductivity and a decrease in the nanofluid viscosity. In this context, a numerical investigation of the competition between viscosity and thermal conductivity about their effects on heat transfer by Al₂O₃-water nanofluid was conducted. A numerical study of heat transfer in a square cavity, filled with Al₂O₃-water nanofluid and heated from the left side, was presented in this paper. Continuity, momentum, and thermal energy equations are solved by the finite… More >

K. Ganesh Kumar^{1, *}, S. Manjunatha², N. G. Rudraswamy³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 131-146, 2020, DOI:10.32604/fdmp.2020.0152

Abstract Boundary layer flows and melting heat transfer of a Prandtl fluid over a stretching surface in the presence of fluid particle suspensions has been investigated. The converted set of boundary layer equations are solved numerically by RKF-45 method. Obtained numerical results for flow and heat transfer characteristics are deliberated for various physical parameters. Furthermore, the skin friction coefficient and Nusselt number are also presented in Tabs. 2 and 3. It is found that the heat transfer rates are advanced in occurrence of nonlinear radiation compered to linear radiation. Also, it is noticed that velocity and temperature profile increases by increasing… More >

Yong Guan¹, Wanling Hu^{1, 2, *}, Yun Zhang¹, Kewei Song^{2, 3}, Liangbi Wang^{2, 3}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 237-256, 2020, DOI:10.32604/cmes.2020.09141

Abstract The application of vortex generators in tube-finned heat exchangers is very universal. The vortex generators can generate secondary flow, and as we all know secondary flow can obviously strengthen heat transfer. To use vortex generators much more efficiently in the circle tube-finned heat exchangers, the intensity correlation study between secondary flow and heat transfer is needed. 22 different structures of circle tubefinned heat exchangers were numerically studied, including the plain fin cases and the cases with vortex generators. In addition, the influence of fin spacing, transverse and longitudinal tube pitch, heights and attack angle of vortex generators, positions of vortex… More >

Primož Kocutar^{1, *}, Jure Ravnik¹, Leopold Škerget¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 1-22, 2020, DOI:10.32604/cmes.2020.08728

Abstract In this paper, we develop and test a unified hybrid LES/URANS turbulence model with two different Large Eddy Simulation (LES) turbulence models. The numerical algorithm is based on the Boundary Element Method. In the existing hybrid LES/URANS turbulence model we implemented a new Smagorinsky LES turbulence model. The hybrid LES/URANS turbulence model is unified, which means that the LES/URANS interface is changed dynamically during simulation using a physical quantity. In order to define the interface between LES and unsteady Reynolds Averaged Navier Stokes (URANS) zones during the simulation, we use the Reynolds number based on turbulent kinetic energy as a… More >