T. Ahmed¹, S. Hassan^1,2, M. F. Hasan³, M. M. Molla^1,2,*, M. A. Taher⁴, S. C. Saha⁵

Energy Engineering, Vol.118, No.1, pp. 15-36, 2021, DOI:10.32604/EE.2020.011237

Abstract The magneto-hydrodynamics (MHD) effect is studied at different inclined angles in Rayleigh-Bénard (RB) convection inside a rectangular enclosure using the lattice Boltzmann method (LBM). The enclosure is filled with electrically conducting fluids of different characteristics. These characteristics are defined by Prandtl number, Pr. The considered Pr values for this study are 10 and 70. The influence of other dimensionless parameters Rayleigh numbers Ra = 10³; 10⁴; 10⁵; 10⁶ and Hartmann numbers Ha = 0, 10, 25, 50, 100, on fluid flow and heat transfer, are also investigated considering different inclined angles φ of magnetic field by analyzing computed local Nusselt… More >

Ahlam Aljabali¹, Abdul Rahman Mohd Kasim^1,*, Nur Syamilah Arifin², Sharena Mohamad Isa³

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 421-435, 2021, DOI:10.32604/cmc.2020.012322

Abstract The viscosity of a substance or material is intensely influenced by the temperature, especially in the field of lubricant engineering where the changeable temperature is well executed. In this paper, the problem of temperature-dependent viscosity on mixed convection flow of Eyring Powell fluid was studied together with Newtonian heating thermal boundary condition. The flow was assumed to move over a vertical stretching sheet. The model of the problem, which is in partial differential equations, was first transformed to ordinary differential equations using appropriate transformations. This approach was considered to reduce the complexity of the equations. Then, the transformed equations were… More >

Yunfei Liao^1,*, Jin Liu²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 961-977, 2020, DOI:10.32604/fdmp.2020.09163

Abstract In order to improve the convective heat transfer relating to an eddy current retarder, the finite element model has been used to assess the performances of different possible designs. In particular, assuming the steady running state of retarder as the working condition, flow and temperature fields have been obtained for the rotor. The influence of airflow path on heat dissipation has been analysed, and the influence of the temperature field distribution on the performance of retarder has been discussed accordingly. The results show that when the steady running state of the turntable is considered, the maximum temperature is lower, the… More >

Donghua Dai^1,2, Dongdong Gu^1,2,*, Qing Ge^1,2, Chenglong Ma^1,2, Xinyu Shi^1,2, Han Zhang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 1085-1098, 2020, DOI:10.32604/cmes.2020.010927

Abstract The three-dimensional physical model of the randomly packed powder material irradiated by the laser beam was established, taking into account the transformation of the material phase, the melt spreading and the interaction of the free surface of the molten pool and the recoiling pressure caused by the material evaporation during the selective laser melting. Influence of the processing parameters on the thermal behavior, the material evaporation, the surface morphology and the densification behavior in the connection region of the molten pool and the substrate was studied. It was shown that the powder material underwent the transformation from the partial melting… More >

Muhammad Ashraf¹, Amir Abbas¹, Saqib Zia², Yu-Ming Chu^{3, 4}, Ilyas Khan^{5, *}, Kottakkaran Sooppy Nisar⁶

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1809-1823, 2020, DOI:10.32604/cmc.2020.011404

Abstract The present study is concerned with the physical behavior of the combined effect of nano particle material motion and heat generation/absorption due to the effect of different parameters involved in prescribed flow model. The formulation of the flow model is based on basic universal equations of conservation of momentum, energy and mass. The prescribed flow model is converted to non-dimensional form by using suitable scaling. The obtained transformed equations are solved numerically by using finite difference scheme. For the analysis of above said behavior the computed numerical data for fluid velocity, temperature profile, and mass concentration for several constraints that… More >

Dolat Khan¹, Gohar Ali¹, Arshad Khan², Ilyas Khan^{3, *}, Yu-Ming Chu^{4, 5}, Kottakkaran Sooppy Nisar⁶

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1237-1251, 2020, DOI:10.32604/cmc.2020.011492

Abstract Nowadays some new ideas of fractional derivatives have been used successfully in the present research community to study different types of mathematical models. Amongst them, the significant models of fluids and heat or mass transfer are on priority. Most recently a new idea of fractal-fractional derivative is introduced; however, it is not used for heat transfer in channel flow. In this article, we have studied this new idea of fractal fractional operators with power-law kernel for heat transfer in a fluid flow problem. More exactly, we have considered the free convection heat transfer for a Newtonian fluid. The flow is… More >

Zia Ullah¹, Muhammad Ashraf¹, Saqib Zia², Yuming Chu^{3, 4}, Ilyas Khan^{5, *}, Kottakkaran Sooppy Nisar⁶

CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 109-123, 2020, DOI:10.32604/cmc.2020.011468

Abstract The present work emphasizes the significance of oscillatory mixed convection stratified fluid and heat transfer characteristics at different stations of non-conducting horizontally circular cylinder in the presence of thermally stratified medium. To remove the difficulties in illustrating the coupled PDE’s, the finite-difference scheme with efficient primitive-variable formulation is proposed to transform dimensionless equations. The numerical simulations of coupled non-dimensional equations are computed in terms velocity of fluid, temperature and magnetic field which are computed to examine the fluctuating components of skin friction, heat transfer and current density for various emerging parameters. The governing parameters namely, thermally stratification parameter More >

Shengyang Feng^1,2,3,*, Dongbo Xiong⁴, Guojie Chen⁵, Yu Cui¹, Puxin Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 651-663, 2020, DOI:10.32604/fdmp.2020.07981

Abstract Convection and diffusion are the main factors affecting radon migration. In this paper, a coupled diffusion-convection radon migration model is presented taking into account turbulence effects. In particular, the migration of radon is simulated in the framework of the k-ε turbulence model. The model equations are solved in a complex 3D domain by the finite element method (FEM). Special attention is paid to the case study about radon migration in an abandoned air defense shelter (AADS). The results show that air convection in a confined space has a great influence on the radon migration and the radon concentration is inversely… 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

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 the Hartmann number. It… More >

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 >