Haruhiko Kohno, Takahiko Tanahashi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.2, No.2, pp. 155-170, 2001, DOI:10.3970/cmes.2001.002.155

Abstract Three-dimensional (3D) unsteady numerical simulations are carried out by means of the finite element method (FEM) with the generalized simplified marker and cell (GSMAC) method in silicon melt with a non-deformable free surface with Prandtl number Pr = 1.8534 × 10^-2, Marangoni number Ma = 0.0 - 6.2067 × 10², Grashof number Gr = 7.1104 × 10⁶, and the aspect ratio As = 1.0 in the Czochralski (CZ) method. The flow state becomes unstable earlier by increasing the absolute value of the thermal coefficient of surface tension in the range of σ_T =0.0 - 1.5 × 10^-5N/mK. Although the velocity… More >

K. Kaminishi¹, M. Iino², H. Bessho², M. Taneda³

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 107-110, 2000, DOI:10.3970/cmes.2000.001.107

Abstract An FEA (finite element analysis) program employing a new scheme for crack growth analysis is developed and a prediction method for crack growth life is proposed. The FEA program consists of the subroutines for the automatic element re-generation using the Delaunay Triangulation technique, the element configuration in the near-tip region being provided by a super-element, elasto-inelastic stress analyses, prediction of crack extension path and calculation of fatigue life. The FEA results show that crack extension rate and path are controlled by a maximum opening stress range, Δσ_θmax, at a small radial distance of r = d, where d is chosen… More >

Cherfi Ryad^1,*, Sadaoui Djamel¹, Sahi Adel¹, Mouloud Smail¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.2, pp. 153-169, 2019, DOI:10.32604/fdmp.2019.04294

Abstract The present work relates to a numerical investigation of double diffusive mixed convection around a horizontal annulus with a finned inner cylinder. The solutal and thermal buoyancy forces are sustained by maintaining the inner and outer cylinders at uniform temperatures and concentrations. Buoyancy effects are also considered, with the Boussinesq approximation. The forced convection effect is induced by the outer cylinder rotating with an angular velocity (ω) in an anti-clockwise direction. The studies are made for various combinations of dimensionless numbers; buoyancy ratio number (N), Lewis number (Le), Richardson number (Ri) and Grashof number (Gr). The isotherms, isoconcentrations and streamlines… More >

Jun Du^1,*, Xin Wu¹, Ruonan Li¹, Ranran Cheng¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 77-87, 2019, DOI:10.32604/fdmp.2019.05949

Abstract In this paper, we take the mid-temperature gravity heat pipe exchanger as the research object, simulate the fluid flow field, temperature field and the working state of heat pipe in the heat exchanger by Fluent software. The effects of different operating parameters and fin parameters on the heat transfer performance of heat exchangers are studied. The results show that the heat transfer performance of the mid-temperature gravity heat pipe exchanger is the best when the fin spacing is between 5 mm and 6 mm, the height of the heat pipe is between 12 mm and 13 mm, and the inlet… More >

Fatima-zohra Bensouici^{1, *}, Saadoun Boudebous²

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.3, pp. 189-212, 2017, DOI:10.3970/fdmp.2017.013.189

Abstract A numerical work has been performed to analyze the laminar mixed convection of nanofluids confined in a lid driven square enclosure with a central square and isotherm heat source. All the walls are cooled at constant temperature, and the top wall slides rightward at constant velocity. The simulations considered four types of nanofluids (Cu, Ag, Al₂O₃ and TiO₂)-Water. The governing equations were solved using finite volume approach by the SIMPLER algorithm. Comparisons with previously published work are performed and found to be in good agreement. The influence of pertinent parameters such as Richardson number, size of the heat source, solid… More >

N. Soltani¹, S. Rahal¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 1-17, 2017, DOI:10.3970/fdmp.2017.013.001

Abstract A three-dimensional time-dependent numerical study of the flow instabilities in a simulated Czochralski system is conducted. The comparison with previously published experimental results is reported. The simulations were performed using a refined grid in order to investigate flow instabilities in the crucible. Simulations have been carried out for various crystal rotational speeds, by taking into account the effects of Rayleigh and Marangoni numbers. The temperature fluctuations near the crystal/liquid interface are analyzed. The method used for that purpose is the Fast Fourier Transform with the corresponding spectra. From numerical simulations, it has been observed that for rotational speeds of the… More >

Saber Hamimid¹, Messaoud Guellal²

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.4, pp. 137-153, 2016, DOI:10.32604/fdmp.2016.012.137

Abstract The numerical study of combined thermo-magnetic convection and surface radiation is presented in this paper and computations are performed for a paramagnetic fluid filled square cavity whose four walls have the same emissivity, placed in a micro-gravity environment (g ≈0), and subjected to various strong non-uniform magnetic field gradients. The vertical walls were isothermal, and the horizontal walls were adiabatic. Finite volume method based on the concepts of staggered grid and SIMPLER algorithm has been applied, and the view factors were determined by analytical formula. Representative results, illustrating the effect of magnetic field strength on streamlines, temperature contours and Nusselt… More >

SouadMorsli^1,*, Amina Sabeur¹, Mohammed El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.4, pp. 342-353, 2015, DOI:10.3970/fdmp.2015.011.342

Abstract The aim of this work is the numerical simulation of the combustion of hydrogen with air in a burner and the numerical solution of local entropy generation rate in the combustion chamber. The effects of equivalence ratio φ and oxygen percentage γ on combustion and entropy generation rates are studied for different φ(ranging from 0 to 1.0) and γ values (ranging from 10 to 30%). The predictions show that the increase of φ (or the decrease of λ ) reduces notably the reaction rate levels. The equations of continuity, of energy and momentum are solved by volume finite using commercial… More >

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays a crucial role in determining… More >

Shuce Zhang¹, Xueheng Tao^1,2,3, Jinshi Lu^1,2, Xuejun Wang^1,2, ZhenhuaZeng⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 143-155, 2015, DOI:10.3970/fdmp.2015.011.143

Abstract Three different kinds of nozzles, normally used in industrial processes for the cleaning of material surface by means of water jets at high pressure (a Cylindrical Contracting, a Taper Contracting and Stepped nozzle), are numerically simulated with the express intent to optimize the related efficiency (cleaning effectiveness). Although some of them are found to display interesting properties, simulation results indicate that a helix nozzle displays the best jetting performances. It is shown that, as compared to improvements obtained by simply changing the jetting angle, revolving the fluid released from the helix nozzle can be used to create a grinding wheel… More >