Numerical simulation of flow field in the pneumatic compact spinning systems using Finite Element Method

2018 ◽  
Vol 30 (3) ◽  
pp. 363-379 ◽  
Author(s):  
Xuzhong Su ◽  
Xinjin Liu ◽  
Xiaoyan Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Field ◽  
High Speed ◽  
Three Dimensional ◽  
Physical Models ◽  
Camera System ◽  
Content Type ◽  
Compact Spinning ◽  
Element Method

Purpose Pneumatic compact spinning is the most widely used compact spinning method at present, in which the negative pressure airflow is used to condense the fiber in order to decrease the spinning triangle and improve the yarn qualities. Therefore, the research on flow field in the condensing zone is always the emphasis for pneumatic compact spinning. The paper aims to discuss these issues. Design/methodology/approach By using finite element method (FEM), the flow field in two kinds of pneumatic compact spinning was studied. Taking three kinds of cotton yarns as examples, with the help of high-speed camera system OLYMPUS i-SPEED3, the motion trajectory of fiber strand in the condensing zone was obtained. Three-dimensional physical models of the condensing zone of the two compact spinning systems were obtained according to the measured parameters of practical spinning systems. Findings It is shown that on the both left edge of B1 line and right edge of B2 line, the airflow inflows to the center line of suction slot, and the condensed effects are produced, correspondingly. In the condensing zone, there are three condensing processes acting on the fiber strand, including the rapid condensing effects in the front condensing zone, the adequately condensing effects in the middle condensing zone, and stable output effects in the back condensing zone. Originality/value By using FEM, numerical simulations of three-dimensional flow field in condensing zone for two kinds of pneumatic compact spinning with lattice apron were presented, and corresponding spun yarn qualities were analyzed.

A MSFEM to simulate the eddy current problem in laminated iron cores in 3D

2019 ◽  
Vol 38 (5) ◽  
pp. 1667-1682 ◽  
Author(s):  
Karl Hollaus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Three Dimensional ◽  
Harmonic Balance Method ◽  
Three Dimensions ◽  
Magnetic Vector Potential ◽  
Content Type ◽  
Element Method

Purpose The simulation of eddy currents in laminated iron cores by the finite element method (FEM) is of great interest in the design of electrical devices. Modeling each laminate by finite elements leads to extremely large nonlinear systems of equations impossible to solve with present computer resources reasonably. The purpose of this study is to show that the multiscale finite element method (MSFEM) overcomes this difficulty. Design/methodology/approach A new MSFEM approach for eddy currents of laminated nonlinear iron cores in three dimensions based on the magnetic vector potential is presented. How to construct the MSFEM approach in principal is shown. The MSFEM with the Biot–Savart field in the frequency domain, a higher-order approach, the time stepping method and with the harmonic balance method are introduced and studied. Findings Various simulations demonstrate the feasibility, efficiency and versatility of the new MSFEM. Originality/value The novel MSFEM solves true three-dimensional eddy current problems in laminated iron cores taking into account of the edge effect.

Coupling of finite element method and integral formulation for vector Helmholtz equation

2018 ◽  
Vol 37 (4) ◽  
pp. 1405-1417
Author(s):  
Sebastian Grabmaier ◽  
Matthias Jüttner ◽  
Wolfgang Rucker
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Helmholtz Equation ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Integral Formulation ◽  
The Finite Element Method ◽  
Content Type ◽  
Wide Range ◽  
Element Method

Purpose Considering the vector Helmholtz equation in three dimensions, this paper aims to present a novel approach for coupling the finite element method and a boundary integral formulation. It is demonstrated that the method is well-suited for many realistic three-dimensional problems in high-frequency engineering. Design/methodology/approach The formulation is based on partial solutions fulfilling the global boundary conditions and the iterative interaction between them. In comparison to other coupling formulation, this approach avoids the typical singularity in the integral kernels. The approach applies ideas from domain decomposition techniques and is implemented for a parallel calculation. Findings Using confirming elements for the trace space and default techniques to realize the infinite domain, no additional loss in accuracy is introduced compared to a monolithic finite element method approach. Furthermore, the degree of coupling between the finite element method and the integral formulation is reduced. The accuracy and convergence rate are demonstrated on a three-dimensional antenna model. Research limitations/implications This approach introduces additional degrees of freedom compared to the classical coupling approach. The benefit is a noticeable reduction in the number of iterations when the arising linear equation systems are solved separately. Practical implications This paper focuses on multiple heterogeneous objects surrounded by a homogeneous medium. Hence, the method is suited for a wide range of applications. Originality/value The novelty of the paper is the proposed formulation for the coupling of both methods.

Analysis of Step Interference Fit of the High Speed Motorized Spindle with Finite Element Method

2004 ◽  
Vol 471-472 ◽  
pp. 844-849 ◽  
Author(s):  
Ping Ma ◽  
Cheng Xiang Liao ◽  
M.L. Duan ◽  
J.K. Li ◽  
D.N. Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Three Dimensional ◽  
Internal Surface ◽  
Three Dimensional Model ◽  
Motorized Spindle ◽  
Interference Fit ◽  
Balance Accuracy ◽  
Element Method

Balance for high speed motorized spindle is most important, it will influence the dynamic behavior of the high speed machine tools. In this paper, the GD-IV high speed spindle is introduced. In order to improve its balance accuracy, the step interference fit is developed to connect the rotor and the shaft. The interference fitted assembly has been modeled theoretically, the analysis highlights that the tolerance of the interference fit consists of the static section and dynamic section, the static section is determined by the transmitting torque while the dynamic section is determined by the centrifugal force. The Calculation of interference fit for the GD-IV spindle shows that the dynamic section is about 4.5 times larger than the static. Furthermore, the three dimensional model of the step interference fit between the shaft and the rotor has also been built up with finite element method and the stress distribution on the mating surface has been calculated. The results show that the maximum stress occurring near the chamfer region of the internal surface of the rotor is up to 235 MPa lower than the permissible material stress 278 MPa, so that the design of the step interference fit is reliability and safety.

Analysis of spherical shell structure based on SBFEM

2020 ◽  
Vol 37 (6) ◽  
pp. 2035-2050
Author(s):  
Gao Lin ◽  
Wen-Bin Ye ◽  
Zhi-Yuan Li ◽  
Jun Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Spherical Shell ◽  
Three Dimensional ◽  
Theory Of Elasticity ◽  
Computational Domain ◽  
Content Type ◽  
Applied Loading ◽  
Surface Finite Elements ◽  
Element Method

Purpose The purpose of this paper is to present an accurate and efficient element for analysis of spherical shell structures. Design/methodology/approach A scaled boundary finite element method is proposed, which offers more advantages than the finite element method and boundary element method. Only the boundary of the computational domain needs to be discretized, but no fundamental solution is required. Findings The method applies to thin as well as thick spherical shells, irrespective of the shell geometry, boundary conditions and applied loading. The numerical solution converges to highly accurate result with raising the order of high-order elements. Originality/value The modeling strictly follows three-dimensional theory of elasticity. Formulation of the surface finite elements using three translational degree of freedoms per node is required, which results in considerably simplifying the computation. In the thickness directions, it is solved analytically, no problem of high aspect ratio arises and transverse shear locking can be successfully avoided.

High-Speed Micromilling of Composite and Aluminum Alloy Parts

2021 ◽  
pp. 62-72
Author(s):  
E.V. Patraev ◽  
M.S. Vakulin ◽  
Y.I. Gordeev ◽  
V.B. Yasinsky
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Experimental Studies ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Three Dimensional Model ◽  
Workpiece Material ◽  
High Productivity ◽  
Element Method

The paper deals with the design of the cutting part of complex-profile cutters with high productivity and surface quality. Numerical experiments carried out using the finite element method made it possible to determine the stresses and strains in the layer of the cut material when machining with multifaceted milling cutters of a new type and indirectly estimate the specific cutting forces. The required dimensions and shape of the cutting wedge are set with account for various geometric parameters of the cutting part, properties of the workpiece material, and cutting conditions. This made it possible to obtain a three-dimensional model of an end mill with a trapezoidal tooth and 700 cutting edges. Experimental studies also showed a change in the morphology of chips with a size of about 2 microns, which is in good agreement with the results of preliminary estimates by the finite element method. The productivity of processing with milling cutters of a new design can be improved by increasing the number of single cutting cycles up to4000–6000 s–1.

Analytical calculation of leakage permeance of coreless axial flux permanent magnet generator

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jun Zhu ◽  
Shuaihui Li ◽  
Xiangwei Guo ◽  
Huaichun Nan ◽  
Ming Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Permanent Magnet ◽  
Magnetic Circuit ◽  
Axial Magnetic Field ◽  
Three Dimensional ◽  
Analytical Calculation ◽  
Content Type ◽  
Leakage Flux ◽  
Element Method

Purpose This paper aims to study the relationship between leakage flux coefficient and the coreless axial magnetic field permanent magnet synchronous generator (AFPMSG) size and obtain the expressions of leakage flux coefficient. Design/methodology/approach In this paper, a magnetic circuit model of coreless AFPMSG is proposed. Four kinds of leakage permeances of permanent magnet (PM) are considered, and the expression of no-load leakage flux coefficient is obtained. Solving the integral region of leakage permeances by generator size, which improves the accuracy of the solution. Findings Finite element method and magnetic circuit method are used to obtain the no-load leakage flux coefficient and its variation trend charts with the change of pole arc coefficient, air gap length and PM thickness. The average errors of the two methods are 2.835%, 0.84% and 1.347%, respectively. At the same time, the results of single-phase electromotive force obtained by magnetic circuit method, three dimensional finite element method and prototype experiments are 19.36 V, 18.82 V and 19.09 V, respectively. The results show that the magnetic circuit method is correct in calculating the no-load leakage flux coefficient. Originality/value The special structure of the coreless AFPMSG is considered in the presented equivalent magnetic circuit and equations, and the equations in this paper can be applied for leakage flux evaluating purposes and initial parameter selection of the coreless AFPMSG.

Comparative analysis of two kinds of pneumatic compact spinning using finite element method

2017 ◽  
Vol 29 (4) ◽  
pp. 514-524
Author(s):  
Li Yinghui ◽  
Chunping Xie ◽  
Xinjin Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Velocity Component ◽  
Breaking Strength ◽  
Content Type ◽  
Axis Direction ◽  
Yarn Properties ◽  
Airflow Field ◽  
Compact Spinning ◽  
Element Method

Purpose The purpose of this paper is to know airflow field and its distribution of pneumatic compact spinning systems. Complete compact spinning (CCS) and four-line rollers compact spinning (FRCS) are both two kinds of pneumatic compact spinning systems, which utilizes airflow in condensing equipment to condense fiber bundle and improve yarn properties. Design/methodology/approach The paper opted for an exploratory study using finite element method, the airflow field in the condensing area of CCS and FRCS were simulated. First, a periodic movement of the fibers in bundle in condensing area was detected, and the yarn tracks were described veritably under the high-speed-video-camera and AutoCAD Software. Then the physical models of the condensing zone were constructed according to the physical parameters of the practical system. The simulation of airflow velocities were extracted along the yarn tracks using ANSYS Software. Finally, the numerical results were verified by spinning experiments. Findings The results show that the negative velocity component along the Y-axis helps keeping beneficial hairiness. CCS has higher negative velocity value and more abundant beneficial hairiness than FRCS. The velocity component in the X-axis direction has a direct effect on yarn evenness. For the same liner density of CCS and FRCS, the larger the value of the velocity component on X-axis is, the better the yarn evenness is. For 9.7tex, CCS has larger velocity component in the X-axis direction and better yarn evenness than FRCS, showing that CCS is more suitable for spinning fine count yarn. The velocity component in the Z-axis direction has a direct effect on breaking strength. CCS has little velocity component in the Z-axis direction and little breaking strength than FRCS. Originality/value To know airflow field and its distribution by finite element method is helpful to investigate the condensing principles of the fiber bundle and improve yarn properties.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

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