Home / Journals / FDMP / Vol.17, No.2, 2021
Table of Content
  • Open Access

    ARTICLE

    Numerical Simulation of the Wake Generated by a Helicopter Rotor in Icing Conditions

    Guozhi Li1, Yihua Cao2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 235-252, 2021, DOI:10.32604/fdmp.2021.014814
    Abstract The wake generated by the rotor of a helicopter can exert a strong interference effect on the fuselage and the horizontal/vertical tail. The occurrence of icing on the rotor can obviously make this interplay more complex. In the present study, numerical simulation is used to analyze the rotor wake in icing conditions. In order to validate the overall mathematical/numerical method, the results are compared with similar data relating to other tests; then, different simulations are conducted considering helicopter forward flight velocities of 0, 10, 20, 50, and 80 knots and various conditions in terms of air temperature (atmospheric temperature degrading… More >

  • Open Access

    REVIEW

    A Review on the Evaporation Dynamics of Sessile Drops of Binary Mixtures: Challenges and Opportunities

    Pradeep Gurrala1, Saravanan Balusamy1, Sayak Banerjee1, Kirti Chandra Sahu2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 253-284, 2021, DOI:10.32604/fdmp.2021.014126
    Abstract The wetting and evaporation dynamics of sessile droplets have gained considerable attention over the last few years due to their relevance to many practical applications, ranging from a variety of industrial problems to several biological systems. Droplets made of binary mixtures typically undergo complex dynamics due to the differential volatility of the considered components and the ensuing presence of thermocapillary effects. For these reasons, many research groups have focused on the evaporation of binary droplets using a variegated set of experimental, numerical, and purely theoretical approaches. Apart from reviewing the state-of-the-art about the existing experimental, analytical, and computational techniques used… More >

  • Open Access

    ARTICLE

    MHD and Viscous Dissipation Effects in Marangoni Mixed Flow of a Nanofluid over an Inclined Plate in the Presence of Ohmic Heating

    D. R. V. S. R. K. Sastry1, Peri K. Kameswaran2, Mohammad Hatami3,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 285-300, 2021, DOI:10.32604/fdmp.2021.014429
    Abstract The problem of Marangoni mixed convection in the presence of an inclined magnetic field with uniform strength in a nanofluid (formed by the dispersion of two metallic nanoparticles, i.e., Copper (Cu), and alumina (Al2O3) in water) is addressed numerically. The effects of viscous dissipation and Ohmic heating are also considered. The original set of governing partial differential equations is reduced to a set of non-linear coupled ordinary differential equations employing the similarity transformation technique. The simplified equations are numerically solved through MATLAB ‘bvp4c’ algorithm. The results are presented in terms of graphs for several parameters. It is found that enhancing… More >

  • Open Access

    ARTICLE

    Lattice Boltzmann Simulation of Nanoparticle Transport and Attachment in a Microchannel Heat Sink

    Xiaokang Tian1, Kai Yue1,2,*, Yu You1,2, Yongjian Niu1, Xinxin Zhang1,2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 301-317, 2021, DOI:10.32604/fdmp.2021.013521
    Abstract The heat transfer performances of a microchannel heat sink in the presence of a nanofluid can be affected by the attachment of nanoparticle (NP) on the microchannel wall. In this study, the mechanisms underlying NP transport and attachment are comprehensively analyzed by means of a coupled double-distribution-function lattice Boltzmann model combined with lattice-gas automata. Using this approach, the temperature distribution and the two-phase flow pattern are obtained for different values of the influential parameters. The results indicate that the number of attached NPs decrease exponentially as their diameter and the fluid velocity grow. An increase in the wall temperature leads… More >

  • Open Access

    ARTICLE

    Buoyancy driven Flow of a Second-Grade Nanofluid flow Taking into Account the Arrhenius Activation Energy and Elastic Deformation: Models and Numerical Results

    R. Kalaivanan1, N. Vishnu Ganesh2, Qasem M. Al-Mdallal3,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 319-332, 2021, DOI:10.32604/fdmp.2021.012789
    (This article belongs to this Special Issue: Advances in Nanofluids: Modelling, Simulation and Applications)
    Abstract The buoyancy driven flow of a second-grade nanofluid in the presence of a binary chemical reaction is analyzed in the context of a model based on the balance equations for mass, species concentration, momentum and energy. The elastic properties of the considered fluid are taken into account. The two-dimensional slip flow of such non-Newtonian fluid over a porous flat material which is stretched vertically upwards is considered. The role played by the activation energy is accounted for through an exponent form modified Arrhenius function added to the Buongiorno model for the nanofluid concentration. The effects of thermal radiation are also… More >

  • Open Access

    ARTICLE

    Computational Fluid Dynamics Simulation of Indoor Air Quality and Thermal Stratification of an Underfloor Air Distribution System (UFAD) with Various Vent Layouts

    Neil Stephen Lopez1,*, Selena Kay Galeos1, Brian Raphael Calderon1, David Roy Dominguez1, Bryan Joseph Uy1, Rupesh Iyengar2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 333-347, 2021, DOI:10.32604/fdmp.2021.011213
    (This article belongs to this Special Issue: Fluid Mechanics and Green Material Processing)
    Abstract The underfloor air distribution (UFAD) system has not been able to penetrate the residential and commercial air conditioning industry significantly until now. To date, the most notable applications are found in datacenters because of their more demanding thermal stratification and cooling requirements. In addition to highlighting the advantages of the UFAD system over the traditional overhead (OH) system, this study compares various ventilation layouts for a UFAD system. Four different UFAD ventilation layouts are compared and one OH layout. The results show that using multiple swirl-type diffusers creates a more uniform floor-to-knee temperature and less air recirculation than the rectangular… More >

  • Open Access

    ARTICLE

    Analysis of the Agglomeration of Powder in a Coaxial Powder Feeding Nozzle Used for Laser Energy Deposition

    Chenguang Guo1,2,*, Yu Sun1,2, Qiang Li1, Haitao Yue1, Chuang Wang1
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 349-370, 2021, DOI:10.32604/fdmp.2021.013535
    Abstract

    To improve the agglomeration of powder in a coaxial powder feeding nozzle used in the frame of a laser energy deposition technique, the influence of several parameters must be carefully assessed. In the present study the problem is addressed by means of numerical simulations based on a DEM-CFD (Discrete Element Method and Discrete Element Method) coupled model. The influence of the powder flow concentration, powder flow focal length and the amount of powder at the nozzle outlet on the rate of convergence of the powder flow is considered. The role played by the nozzle outlet width, the angle between the… More >

  • Open Access

    ARTICLE

    A Pressure-Drop Model for Oil-Gas Two-Phase Flow in Horizontal Pipes

    Xinke Yang1, Shanzhi Shi1, Hui Zhang1, Yuzhe Yang2,3, Zilong Liu2,3, Ruiquan Liao2,3,*, Joseph X. F. Ribeiro4
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 371-383, 2021, DOI:10.32604/fdmp.2021.011486
    Abstract The accurate prediction of the pressure distribution of highly viscous fluids in wellbores and pipelines is of great significance for heavy oil production and transportation. The flow behavior of high-viscosity fluids is quite different with respect to that of low-viscosity fluids. Currently, the performances of existing pressure-drop models seem to be relatively limited when they are applied to high-viscosity fluids. In this study, a gas-liquid two-phase flow experiment has been carried out using a 60 mm ID horizontal pipe with air and white oil. The experimental results indicate that viscosity exerts a significant influence on the liquid holdup and pressure… More >

  • Open Access

    ARTICLE

    Zeolite A Synthesized from Geothermal Waste Using Conventional and Microwave Heating for the Hydrothermal Treatment

    Sulardjaka Sulardjaka1,*, Sri Nugroho1, Norman Iskandar1, Agus P. Adi1, Deni F. Fitriyana2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 385-395, 2021, DOI:10.32604/fdmp.2021.011784
    Abstract Zeolite A has been successfully synthesized from geothermal waste with natrium aluminate and natrium silicate using conventional (C-H) and microwave heating (M-H) for the hydrothermal treatment. The products obtained for different aging times have been characterized using X-Ray Diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). It is shown that with the M-H process, zeolite can be formed at relatively low temperature (100°C) in a relatively short time (40 min). The crystallization of zeolite A has been found to be generally promoted by an increase of aging and synthesis time; however, it has also been observed… More >

  • Open Access

    ARTICLE

    Numerical Simulation of the Mixing and Hydrodynamics of Asphalt and Rubber in a Stirred Tank

    Zechen Yao1, Renfeng Yang1,*, Haichao An2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 397-412, 2021, DOI:10.32604/fdmp.2021.012114
    Abstract Computational fluid dynamics (CFD) has been used to analyze the mixing process of Asphalt and Rubber (AR) in a stirred tank with a six flat-blade disc turbine (Rushton), a down-pumping 45° pitched-blade turbine (PBTD-6) and a down-pumping propeller (TXL). The two-phase (solid-liquid) flow in the considered stirred tank has been modelled in the framework of an Eulerian-Eulerian approach, a laminar-flow assumption and a multi-reference frame strategy. The following effects have been investigated: The influence of the impeller speed, impeller type, crumb rubber (CR) particle diameter and initial CR particle loading on the quality of the CR particle’s suspension. The outcomes… More >

  • Open Access

    ARTICLE

    On the Influence of Vortex-Induced Resistance on Oil-Shale Particle-Slurry Flow in Vertical Pipes

    Li-an Zhao1,*, Tieli Wang2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 413-426, 2021, DOI:10.32604/fdmp.2021.011205
    Abstract The transportation in vertical pipelines of particle slurry of oil shale has important applications in several fields (marine mining, hydraulic mining, dredging of river reservoir, etc.). However, there is still a lack of information about the behavior of coarse particles in comparison to that of fine particles. For this reason, experiments on the fluidization and hydraulic lifting of coarse oil shale particles have been carried out. The experimental data for three kinds of particles with an average size of 5 mm, 15 mm and 25 mm clearly demonstrate that vortices can be formed behind the particles. On this basis, a… More >

  • Open Access

    ARTICLE

    Experimental and Numerical Analysis of Surface Magneto-Hydrodynamic Propulsion Induced by NdFeB Magnets

    Zongkai Liu1,2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 427-439, 2021, DOI:10.32604/fdmp.2021.010528
    Abstract The so-called surface Magneto-hydro-dynamic (MHD) propulsion relies on the Lorentz force induced in weak electrolyte solutions (such as seawater or plasma) by NdFeB Magnets. The Lorentz force plays an important role in such dynamics as it directly affects the structures of flow boundary layers. Previous studies have mainly focused on the development of such boundary layers and related fluid-dynamic aspects. The main focus of the present study is the determination of electromagnetic field distributions around the propulsion units. In particular dedicated experiments and numerical simulations (based on the finite volume method) are conducted considering a NACA0012 airfoil immersed in seawater.… More >

  • Open Access

    ARTICLE

    A Pull-Out Test Study on the Working State of Fully Grouted Bolts

    Ruixin Zhao1,*, Zhongju Feng1, Guan Jiang1, Fuchun Wang1, Yidong Zhang2, Changan Zhang3, Zhenbing Wang1
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 441-453, 2021, DOI:10.32604/fdmp.2021.010595
    Abstract The present study examines the working conditions of fully grouted bolts used for the construction and expansion of high slopes. On the basis of a pull out destructive test, the work load and the ultimate load are obtained on site, and the Flac3d numerical simulation method is employed to determine the axial force distribution and the effective anchor length. The test results show that (1) the Q-S (load-displacement) curve of the bolt displays a certain degree of deformation coupled with the creep of the surrounding rock; (2) the working load of the bolt is closely related to the sliding deformation… More >

  • Open Access

    ARTICLE

    Numerical Simulation of Turbulent Swirling Pipe Flow with an Internal Conical Bluff Body

    Jinli Song1, Nabil Kharoua2,*, Lyes Khezzar1, Mohamed Alshehhi1
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 455-470, 2021, DOI:10.32604/fdmp.2021.014370
    Abstract Turbulent swirling flow inside a short pipe interacting with a conical bluff body was simulated using the commercial CFD code Fluent. The geometry used is a simplified version of a novel liquid/gas separator used in multiphase flow metering. Three turbulence models, belonging to the Reynolds averaged Navier-Stokes (RANS) equations framework, are used. These are, RNG k-ε, SST k-ω and the full Reynolds stress model (RSM) in their steady and unsteady versions. Steady and unsteady RSM simulations show similar behavior. Compared to other turbulence models, they yield the best predictions of the mean velocity profiles though they exhibit some discrepancies in… More >

  • Open Access

    ARTICLE

    A Numerical Study on the Mechanisms Producing Forces on Cylinders Interacting with Stratified Shear Environments

    Yin Wang1,*, Lingling Wang2, Yong Ji1, Zhicheng Xi1, Wenwen Zhang1
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 471-485, 2021, DOI:10.32604/fdmp.2021.014652
    Abstract A three dimensional (3D) numerical wave flume is used to investigate carefully the ISWs (Internal solitary wave) forces acting on cylinders interacting with a stratified shear environment. Using the Large-Eddy Simulation (LES) approach and analyzing the distribution of shear stress and pressure along the surface of the cylinder, the differential pressure resistance and the viscous force are obtained. The method of multiple linear regression analysis is adopted and a comprehensive influence coefficient is determined accordingly to account for the dimensionless forces acting on the cylinder. Results show that the differential pressure resistance on a square cylinder is 1.5 times higher… More >

  • Open Access

    ARTICLE

    On the Effect of the Rotating Chamber Reverse Speed on the Mixing of SiC Ceramic Particles in a Dry Granulation Process

    Dongling Yu1, Zuoxiang Zhu1, Jiangen Zhou1, Dahai Liao1,*, Nanxing Wu1,2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 487-500, 2021, DOI:10.32604/fdmp.2021.014712
    Abstract In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process, the effect of the wall reverse speed on the mixing process is investigated. In particular, an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air. The numerical results show that by setting a certain reverse rotating speed of the rotating chamber, the accumulation of SiC particles on the wall can be improved, i.e., their direction of motion in proximity to the wall can be changed and particles can… More >

  • Open Access

    ARTICLE

    Effect of Al2O3 Nanoparticle on Cavitation Strengthening of Magnesium Alloys

    Lei Liu*, Chuanhui Huang, Xinghua Lu, Ping Yu, Longhai Li, Huafeng Guo
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 501-509, 2021, DOI:10.32604/fdmp.2021.015161
    Abstract In order to study the effect of Al2O3 nanoparticles in the cavitation-based strengthening process of magnesium alloys, the impact of a micro-jet generated by bubble collapse has been considered. The strengthening mechanism is based on the transfer of the energy of cavitation due to bubble collapse to Al2O3 particles, which then undergo collision with the surface of the sample. The hardness, surface morphology, element content and chemical state of the strengthened samples have been analyzed by microhardness tests, SEM (scanning electron microscopy) and XPS (X-ray photoelectron spectroscopy) techniques. The results show that: after 5 min of strengthening, nanoparticles can be… More >

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