Numerical Simulation of a Combined Plasma Arc Based on Sequentially Coupled Physics Analysis

2010 ◽  
Vol 129-131 ◽  
pp. 708-713
Author(s):  
Jian Bing Meng ◽  
Xiao Juan Dong ◽  
Wen Ji Xu

A three-dimensional axisymmetric mathematical model, including the influence of the swirl exiting in the plasma torch, was developed to describe the heat transfer and fluid flow within a combined plasma arc. In this model, a mapping method and a meshing method of variable step-size were adopted to mesh the calculation domain and to improve the computational precision. To overcome the problem issuing from a coexistence of non-transferred arc and transfer arc and a complicated interaction between electric, magnetic, heat flow and fluid flow phenomena in the combined plasma arc, a sequential coupling method and a physical environment approach were introduced into the finite element analysis on the behaviors of combined plasma arc. Furthermore, the characteristics of combined plasma arc such as temperature, velocity, current density and electromagnetic force were studied.

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.


2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.


2014 ◽  
Vol 644-650 ◽  
pp. 137-141
Author(s):  
Guo Sheng Zhang ◽  
Wei Zhou ◽  
Ye Chen ◽  
Jian Qiang Gong

According to the super large or heavy vehicle accidents existing wrecker cannot complete the wrecker rescue mission independent problems, puts forward the design of a practical game type crane wrecker. The hoisting mechanism as the research object, the traditional mechanical method is designed and calculated, then the three-dimensional entity model using 3D mechanical design software Solidworks, and imported into the finite element analysis software ANSYS to analyze the static mechanics characteristics of the structure, to improve the local strength of short position. On this basis, a lifting test vehicle prototype, rated load operation and overload operation condition test, and measure its subsidence. With the analysis of the experiment results, show that the design truck lifting organ can meet the demand of the technology.


Geophysics ◽  
1974 ◽  
Vol 39 (1) ◽  
pp. 56-68 ◽  
Author(s):  
Flavian Abramovici

The impedance tensor corresponding to the magnetotelluric field for a nonisotropic one‐dimensional structure is given in terms of the solutions of a sixth‐order differential system. The conductivity tensor is three‐dimensional. Its components depend upon depth only in an arbitrary manner such that the corresponding matrix is positive definite. The impedance tensor components are found by a numerical integration procedure based on a set of one‐step methods and a variable step‐size to insure a given accuracy in the final result. Calculations were made for three models having sharp boundaries and also transitional layers. The first of these models has a middle layer of high conductivity, sandwiched between two layers of linearly varying conductivity, while in the second model the middle layer has a very low conductivity. In the third model the conductivity tensor is three‐dimensional and is linearly varying in one of the layers.


2012 ◽  
Vol 562-564 ◽  
pp. 1943-1946
Author(s):  
Yong Hu ◽  
Jin Gan Song ◽  
Qing Zou ◽  
Ke Zhu ◽  
Xiao Long Wang

Because both of the volume and the weight of the photoelectric platform are small, the structure of two frames and two axes is used in the photoelectric platform. As the key component of the photoelectric platform, the main frame should have sufficient strength and rigidity. In order to achieve this object, three-dimensional entity model of the main frame is established using CATIA software. Then the finite-element analysis of the model is finished with ANSYS Workbench. Based on the analysis results, the weak links of the main frame is found. Then these links are improved and the main frame is analyzed again. After improving the structure, the results of the finite-element analysis show that the main frame meets the requirements of design and has perfect overall performance.


2014 ◽  
Vol 926-930 ◽  
pp. 52-55
Author(s):  
Lian Feng Lai ◽  
Cheng Hui Gao ◽  
Jian Meng Huang

A three-dimensional W-M fractal sliding model of double rough surfaces was established, and the factors of interface shear strength influenced the whole sliding process was considered. The velocity in Z direction of sliding processes was analyzed using the finite element analysis and taking into account of adhesion factors in the process of contact. The numerical results showed that the velocity in Z direction's fluctuation is larger, and the higher-frequency component is more with the decrease of the interface shear strength. Compared with experimental results and related documents, it is concluded the rationality of the results. The contact model between two rough solids will lay a foundation to further research on the substance of the process of friction and wear.


Author(s):  
Marcus Gamino ◽  
Samuel Abankwa ◽  
Raresh Pascali

A general assumption in performing vortex-induced vibration (VIV) analysis of pipeline free spans is both ends of the free span are fixed and/or pinned in order to simplify computational simulations; however, DNV Recommended Practice F105 states that these boundary conditions must adequately represent the pipe-soil interaction and the continuality of the pipeline. A computational methodology is developed to determine the effects of pip-soil interaction at the ends of a free span. Three-dimensional fluid-structure interaction (FSI) simulations are performed by coupling the computational fluid dynamics (CFD) codes from STAR-CCM+ with the finite element analysis (FEA) codes from ABAQUS. These FSI simulations in combination with separate coupled Eulerian-Lagrangian (CEL) simulations are modeled to mimic real word conditions by setting up boundary conditions to factor in the effects of pipe-soil interaction at the ends of the span. These simulations show a mitigation of overall stresses to the free spans; as a result, the integration of pipe-soil interaction in free span assessment may prove cost effective in the prevention of unnecessary corrective action.


2014 ◽  
Vol 614 ◽  
pp. 576-579
Author(s):  
Xiu Hua Ma

In this paper, SolidWorks2012 was redeveloped by visual programming tool Visual Basic6.0 to realize the three-dimensional parametric design of wellhead gate valve and the transformation of corresponding engineering drawings on the engineering diagram template. Then the finite element analysis was progressed directly by using the SolidWorks module of the finite element analysis. This can shorten design time of gate valve and improve work efficiency.


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