The International Journal of Multiphysics
http://journal.multiphysics.org/index.php/IJM
<p>ISSN: 1750-9548</p><a href="https://www.scopus.com/sourceid/19700183150">Available Online on Scopus®</a>The International Society of Multiphysicsen-USThe International Journal of Multiphysics1750-9548<p><span>The articles are published under </span><a href="http://creativecommons.org/licenses/by/3.0/" rel="license">Creative Commons Attribution License</a><span> (CC-BY 4.0). </span></p><p><span>The authors hold the copyrights without restrictions. </span></p><p>The journal copyright policy is available on <a href="http://www.sherpa.ac.uk/romeo/issn/1750-9548/">SHERPA/RoMEO</a>.</p>Interval Search with Quadratic Interpolation and Stable Deviation Quantum-Behaved Particle Swarm Optimization (IQS-QPSO)
http://journal.multiphysics.org/index.php/IJM/article/view/419
<p class="abstract">In this article, in order to enhance the rate of convergence and scattering of particles at the same time, simple techniques are introduced. These techniques include: (1) Using the interval search to select a new particle candidate, (2) Replacement of three candidate particles instead to worst the particles in the population, (3) Using the best result of learning coefficients, (4) using a simple method to control the convergence of the algorithm in a high number of repetitions.</p><p class="abstract">In this article, the performance of Quantum-Behaved Particle Swarm Optimization(QPSO) algorithm has been upgraded with using the interval search method. The proposed method of interval search of quantum-behaved particle swarm optimization algorithm has achieved better results than in the past with the use of quadratic interpolation recombination operator and stable deviation and interval search.</p>Moreover, the results of the proposed algorithm of Interval Search with Quadratic Interpolation and Stable Deviation Quantum-Behaved Particle Swarm Optimization (IQS-QPSO) is compared with the other former algorithms such as Quantum-Behaved Particle Swarm Optimization (QPSO), Quadratic Interpolation Quantum-Behaved Particle Swarm Optimization (Q-QPSO) and Stable Deviation Quantum-Behaved Particle Swarm Optimization (SD-QPSO). Then the performance improvement is reported. In order to compare the results of each algorithm, five famous functions are used and consequently the results are reported separately for each functionP AminiA BagheriS Moshfegh
Copyright (c) 2019 P Amini, A Bagheri, S Moshfegh
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2019-06-212019-06-2113210.21152/1750-9548.13.2.113Numerical simulation of an RF asymmetric nonthermal plasma reactor used for plasma polymerisation
http://journal.multiphysics.org/index.php/IJM/article/view/429
The aims of this paper is to investigate the control of plasma properties via the geometrical asymmetry effect in a capacitive coupled discharge used for polymer processing. The simulation results prove that the bulk position and density profiles of positive ions, negative ions, and electrons have a clear dependence on geometric asymmetry effect. The underlying mechanisms identified shows a more collisional sheath at the smaller powered surface due to the larger sheath width, and a higher energy at the smaller surface due to the higher mean sheath voltage compared to the larger surface. The argon modelling results are compared to experimental results from the literature for a range of operating conditions. The results show that the argon model results can be used to predict the plasma parameters for other gases used for polymer processing.S ElaissiH Alyousef
Copyright (c) 2019 S Elaissi, H Alyousef
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2019-06-212019-06-2113210.21152/1750-9548.13.2.131Performance of Cross-linked Polyethylene Insulated Cable based on Detection of High Voltage Electric Field
http://journal.multiphysics.org/index.php/IJM/article/view/431
<p align="justify">High voltage direct current transmission has been widely used in long-distance power transmission because of its advantages such as low loss and large throughput. The safety of cable is very important in the long-distance transmission process. Cross-linked polyethylene insulated cable has the advantages of simple manufacture, good heat resistance and easy installation; therefore it has been widely used in long-distance power transmission. In this study, conductance, dielectric and voltage withstanding performance of the insulating layers of cross-linked polyethylene cables with working voltage of 220 kV which was never used and has been used for 2, 4, 6 and 8 years were tested by various evaluation methods. The conductivity of the insulating layers was affected by temperature only under high and low electric field intensities and was affected by temperature and electric field strength under middle electric field intensity. Dielectric loss factor could reflect dielectric properties of materials; the larger the dielectric loss factor, the poorer the performance. The dielectric loss factor decreased with the increase of applied electric field frequency and increased with the increase of service years. Breakdown electric field strength could reflect voltage resistance of materials; the larger the breakdown electric field strength, the better the performance. The breakdown electric field strength was inversely proportional to the service years of the insulating layer, and the decrease amplitude increased significantly when the service time exceeded 2 years. In summary, cross-linked polyethylene insulated material satisfies the safety requirement of high voltage direct current transmission and can be used for manufacturing long-distance transmission cables.</p>Y LuoJ LuoB Li
Copyright (c) 2019 Y Luo, J Luo, B Li
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2019-06-212019-06-2113210.21152/1750-9548.13.2.147Impact and ricochet of a high-speed rigid projectile from an air-water interface
http://journal.multiphysics.org/index.php/IJM/article/view/452
<p>A numerical study on a rigid projectile (sphere) ricocheting off a water layer is presented in this paper. The time-dependent three-dimensional simulations are carried out for the impact of a solid metal sphere (with radius <em>r</em>) on a quiescent air-water interface. Three types of metal spheres with specific gravity values ranging from 7.8 to 2.7 (steel, titanium and duralumin) were considered. The numerical results are compared with analytical solutions and experimental data of the ricochet problem available in the literature. A given range of projectile impact velocity <em></em>are considered with varying impact angles to determine the critical angle of impact as a function of the Froude number and specific gravity. A correlation in the form of is proposed for the ricochet of a solid sphere from an air-water interface.</p>B FaroukH BassindowahS Segletes
Copyright (c) 2019 B Farouk, H Bassindowa, S Segletes
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2019-06-212019-06-2113210.21152/1750-9548.13.2.157Finite element analysis on parameterized model of fiber composite battledore
http://journal.multiphysics.org/index.php/IJM/article/view/457
<p align="justify">Composite materials have superior properties than single materials, and they have been applied in many fields, for example, sporting goods. In this paper, a battledore was manufactured using fiber composites, and finite element analysis was carried out. The parameterized model of the battledore was established by ANSYS finite element software. Then the displacement, stress and failure of the battledore were analyzed. The results showed that the maximum displacement of the battledore was about 0.9 mm, located at the top of battledore frame, the maximum stress was about 155 MPa, located at the junction of battledore frame and rod, and the maximum failure factor was 0.38, which is higher than that of common aluminum alloy battledore. All the findings suggested that the designed battledore was effective. The battledore has a high safety factor and is worthy of application in practice.</p>H Shen
Copyright (c) 2019 H Shen
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2019-06-212019-06-2113210.21152/1750-9548.13.2.179Multiphysics Study of Tensile Testing using Infrared thermography
http://journal.multiphysics.org/index.php/IJM/article/view/465
In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was generated using a hand-operated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data acquisition, the measured values for force and displacement were recorded in a PC. The IR thermographic imaging was performed using the FLIR® T1030sc IR camera and ResearchIR Max software. The steel specimens were coated with high emissivity paint. Thermography revealed that the steel specimens show noticeable thermal signature when undergoing tensile loading. The samples were found to be warmer by 20-25 °C at the time of failure. The tests were repeated under various surrounding temperatures such as 25 °C, -5 °C, -10 °C, -15 °C, and -20 °C. The same study was compared with the finite element numerical simulation in ANSYS® Workbench. The experimental and simulation results were found to be in a qualitative agreement.E StangeZ AndleebH KhawajaM Moatamedi
Copyright (c) 2019 E Stange, Z Andleeb, H Khawaja, M Moatamedi
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2019-06-212019-06-2113210.21152/1750-9548.13.2.191Comparison of Explicit Method of Solution for CFD Euler Problems using MATLAB® and FORTRAN 77
http://journal.multiphysics.org/index.php/IJM/article/view/466
<p>This work presents a comparison of an explicit method of solution for an inviscid compressible fluid mechanics problem using Euler equations for two-dimensional internal flows. The same algorithm was implemented in both FORTRAN 77 and MATLAB®. The algorithm includes Runge‒Kutta time marching scheme with smoothing. Both solvers were initialized in the same manner. In addition, it was ensured that both solvers have the exact same values for time step, convergence criteria, boundary conditions, and the grid. The only difference between the two solvers was the precision of variables.</p><p>The problem solved was a two-dimensional dual bump with an accelerating flow through a duct. The same algorithm solving the Euler equations of fluid flow is implemented in both FORTRAN 77 and MATLAB®, and applied to identical input. While the solutions look qualitativly the same, a 20% difference in the stationary solution is observed. No claim is made of the relevance of the computations to actual fluid flow, rather the key takeaway being that two finite and deterministic computations of the same algorithm on the same input in FORTRAN 77 and MATLAB® produce different output.</p>A NordliH Khawaja
Copyright (c) 2019 A Nordli, H Khawaja
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2019-06-212019-06-2113210.21152/1750-9548.13.2.203