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 - 21 April 2020

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 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 - 21 April 2020

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… More >

Jiacheng Dai¹, Jiegang Mou^{1, *}, Tao Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 161-179, 2020, DOI:10.32604/fdmp.2020.06613 - 21 April 2020

Abstract The automobile engine pump is an important part of the automobile cooling system, and has a direct influence on the engine performance. Based on the SST k-ω turbulence model, unsteady numerical simulation for an automobile engine pump with different tip clearances was carried out by Fluent. To study the flow field characteristics and pressure fluctuation, the characteristics of secondary flow distribution in volute are also analyzed. The result shows that the pressure fluctuation characteristics of the flow field show obvious periodic variation at different levels of tip clearances. The peak value of pressure fluctuation at… More >

A. Aissa^{1, *}, M. E. A. Slimani², F. Mebarek-Oudina³, R. Fares¹, A. Zaim¹, L. Kolsi^{4, 5}, M. Sahnoun¹, M. E. Ganaoui⁶

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 147-159, 2020, DOI:10.32604/fdmp.2020.04073 - 21 April 2020

Abstract In this paper, flow of slightly rarefied compressible nitrogen in microchannels has been investigated numerically for low values of Reynolds and Mach numbers. The 2D governing equations were solved using Finite Element Method with first-order slip boundary conditions (Comsol Multiphysics software). A validation was performed by comparing with similar configuration from the literature. It was found that our model can accurately predict the pressure driven flow in microchannels. Several interesting findings are reported about the Relative pressure, longitudinal velocity, Mach number, effect of gas rarefaction and flow rate. 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 - 21 April 2020

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 More >

Tian Li^{1, *}, Xiaohan Zhang¹, Yao Jiang², Weihua Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 121-130, 2020, DOI:10.32604/fdmp.2020.07976 - 01 February 2020

Abstract The so-called Evacuated Tube Train (ETT) is currently being proposed as a high-speed transportation system potentially competitive with airplane transportation. Aerodynamic resistance is one of the most crucial factors for the successful design of an ETT. In the present work, a three-dimensional concept ETT model has been elaborated. The aerodynamic characteristics of the subsonic ETT have been numerically simulated under different conditions. The train’s running speed varies from 600 km/h up to 1200 km/h, and the blockage ratio is in the range between 0.1 and 0.3. As the blocking ratio and running speed increase, the More >

Yadong Zhang^{1, *}, Jiye Zhang²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 105-120, 2020, DOI:10.32604/fdmp.2020.07959 - 01 February 2020

Abstract The object of research of this paper is the DSA380 high-speed pantograph. The near-field unsteady flow around the pantograph was investigated using large eddy simulation (LES) while the far-field aerodynamic noise was analysed in the frame of the Ffowcs Williams-Hawkings (FW-H) acoustic analogy. According to the results, the contact strip, base frame and knuckle are the main aerodynamic noise sources, with vortex shedding, flow separation and recombination around the pantograph being related key physical factors. The aerodynamic noise radiates outwards in the form of spherical waves when the distance of the noise receiving point is… More >

D. O. Redchyts¹, E. A. Shkvar^{2, *}, S. V. Moiseienko³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 91-103, 2020, DOI:10.32604/fdmp.2020.07933 - 01 February 2020

Abstract A method to evaluate the properties of turbulent flow in proximity to the vehicle and close to the ground surface has been elaborated. Numerical simulations have been performed on the basis of the Unsteady Reynolds-averaged Navier-Stokes equations (URANS) written with respect to an arbitrary curvilinear coordinate system. These equations have been solved using the Spalart-Allmaras differential one-parametric turbulence model. The method of artificial compressibility has been used to improve the coupling of pressure and velocity in the framework of a finite volume approach. Time-averaged distributions of pressure fields, velocity components, streamlines in the entire area… More >

Haiqing Li¹, Mengge Yu^{1, *}, Qian Zhang¹, Heng Wen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 77-90, 2020, DOI:10.32604/fdmp.2020.07797 - 01 February 2020

Abstract The performances of high-speed trains in the presence of coupling effects with crosswind and rain have attracted great attention in recent years. The objective of the present paper was to investigate the aerodynamic characteristics of a high-speed train under such conditions in the framework of an Eulerian-Lagrangian approach. An aerodynamic model of a high-speed train was first set up, and the side force coefficient obtained from numerical simulation was compared with that provided by wind tunnel experiments to verify the accuracy of the approach. Then, the effects of the yaw angle, the resultant wind speed, More >

Xiaohan Zhang¹, Yao Jiang², Tian Li^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 67-76, 2020, DOI:10.32604/fdmp.2020.07776 - 01 February 2020

Abstract The aerodynamic resistance of a train running in the open air limits the maximum speed that can be attained by the train. For this reason, evacuated tube trains (ETT) are being considered as valid alternatives to be implemented in the future. The atmosphere in the tube, the so-called blocking ratio and the length of the streamlined nose are the key factors affecting the aerodynamic performances of these trains. In the present work, we investigate evacuated tube trains with different lengths of the streamline nose on the basis of computational fluid dynamics (CFD). The three-dimensional steady… More >