New Type of Two Degree of Freedom Motor Three-Dimensional Tooth Layer Field Application and Solution

2013 ◽  
Vol 391 ◽  
pp. 232-236
Author(s):  
Wen Huan Yang ◽  
Hai Xu Chen ◽  
Shuang Xie ◽  
Chun Ren Fang
Keyword(s):  
Linear Equations ◽  
Three Dimensional ◽  
Field Application ◽  
Degree Of Freedom ◽  
Refined Method ◽  
New Type ◽  
Type Motor ◽  
Quasi Newton ◽  
Two Degree Of Freedom ◽  
Non Linear Equations

A new Multi-degree of freedom motor and its establishing of teeth layer parameters have been introduced in the paper, also including application method of database, namely using Quasi-Newton methods to solve the non-linear equations of the new motors magnetic circuit net, formed a refined method for designing and analyzing of motor. The establishment of 3d tooth layer parameters database, is provided for the calculation in the design of the new type motor conveniently.

Three-Dimensional Numerical Simulations of Circular Cylinders Undergoing Two Degree-of-Freedom Vortex-Induced Vibrations

2006 ◽  
Author(s):  
Juan P. Pontaza ◽  
Hamn-Ching Chen
Keyword(s):  
Numerical Simulations ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Degree Of Freedom ◽  
Circular Cylinders ◽  
Time Step ◽  
Reynolds Number Flow ◽  
Number Flow ◽  
High Reynolds ◽  
Two Degree Of Freedom

In an effort to gain a better understanding of the VIV phenomena, we present three-dimensional numerical simulations of VIV of circular cylinders. We consider operating conditions that correspond to high Reynolds number flow, low structural damping, and allow for two-degree of freedom motion. The numerical implementation makes use of overset (Chimera) grids, in a multiple block environment where the workload associated with the blocks is distributed among multiple processors working in parallel. The three-dimensional grids around the cylinder are allowed to undergo arbitrary motions with respect to fixed background grids, eliminating the need for tedious grid regeneration at every time step.

Degenerate “Star” Bifurcations in a Twinkling Oscillator

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Smruti R. Panigrahi ◽  
Brian F. Feeny ◽  
Alejandro R. Diaz
Keyword(s):  
Normal Form ◽  
Multiple Equilibria ◽  
Degree Of Freedom ◽  
Negative Stiffness ◽  
Nonlinear Spring ◽  
Mass Chain ◽  
New Type ◽  
Two Degree Of Freedom

We have studied a nonlinear spring-mass chain loaded by a quasistatic pull. The spring forces are assumed to be cubic with intervals of negative stiffness. Depending on the parameters, the system has multiple equilibria. The normal form and the bifurcation behaviors for the single- and two-degree-of-freedom systems are studied in detail. A new type of bifurcation, which we refer to as a star bifurcation, has been observed for the symmetric two-degree-of-freedom system. This bifurcation is of codimension-four for the undamped case and codimension-three or two for the damped case, depending on the form of the damping.

Three-Dimensional Numerical Simulations of Circular Cylinders Undergoing Two Degree-of-Freedom Vortex-Induced Vibrations

2006 ◽  
Vol 129 (3) ◽  
pp. 158-164 ◽  
Author(s):  
Juan P. Pontaza ◽  
Hamn-Ching Chen
Keyword(s):  
Numerical Simulations ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Degree Of Freedom ◽  
Circular Cylinders ◽  
Numerical Implementation ◽  
Vortex Induced Vibrations ◽  
Multiple Processors ◽  
Structural Mass ◽  
Two Degree Of Freedom

In an effort to gain a better understanding of vortex-induced vibrations (VIV), we present three-dimensional numerical simulations of VIV of circular cylinders. We consider operating conditions that correspond to a Reynolds number of 105, low structural mass and damping (m*=1.0, ζ*=0.005), a reduced velocity of U*=6.0, and allow for two degree-of-freedom (X and Y) motion. The numerical implementation makes use of overset (Chimera) grids, in a multiple block environment where the workload associated with the blocks is distributed among multiple processors working in parallel. The three-dimensional grid around the cylinder is allowed to undergo arbitrary motions with respect to fixed background grids, eliminating the need for grid regeneration as the structure moves on the fluid mesh.

scholarly journals Three-Dimensional Broadband and Isotropic Double-Mesh Twin-Wire Media for Meta-Lenses

2021 ◽  
Vol 11 (15) ◽  
pp. 7153
Author(s):  
Hairu Wang ◽  
Qiao Chen ◽  
Oskar Zetterstrom ◽  
Oscar Quevedo-Teruel
Keyword(s):  
High Performance ◽  
Periodic Structures ◽  
Three Dimensional ◽  
Degree Of Freedom ◽  
Inhomogeneous Materials ◽  
Electromagnetic Propagation ◽  
Graded Index ◽  
New Type ◽  
Wire Media ◽  
Low Dispersion

Lenses are used for multiple applications, including communications, surveillance and security, and medical instruments. In homogeneous lenses, the contour is used to control the electromagnetic propagation. Differently, graded-index lenses make use of inhomogeneous materials, which is an extra degree of freedom. This extra degree of freedom enables the design of devices with a high performance. For instance, rotationally symmetric lenses without spherical aberrations, e.g., the Luneburg lens, can be designed. However, the manufacturing of such lenses is more complex. One possible approach to implement these lenses is using metamaterials, which are able to produce equivalent refractive indices. Here, we propose a new type of three-dimensional metamaterial formed with two independent sets of wires. The double-mesh twin-wire structure permits the propagation of a first mode without cut-off frequency and with low dispersion and high isotropy. These properties are similar to periodic structures with higher symmetries, such as glide symmetry. The variations of the equivalent refractive index are achieved with the dimension of the meandered wires. The potential of this new metamaterial is demonstrated with simulated results of a Luneburg meta-lens.

Analytic Approximate Solutions and Numerical Results for Stagnation Point Flow of Jeffrey Fluid Towards an Off-Centered Rotating Disk

2014 ◽  
Vol 31 (2) ◽  
pp. 201-215 ◽  
Author(s):  
N. A. Khan ◽  
S. Khan ◽  
F. Riaz
Keyword(s):  
Linear Equations ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Approximate Solutions ◽  
Jeffrey Fluid ◽  
Analysis Method ◽  
Convergence Region ◽  
Homotopy Analysis ◽  
Special Case ◽  
Non Linear Equations

AbstractThe present paper studies the three-dimensional, off centered stagnation flow of a Jeffrey fluid over a rotating disk. The governing non-linear equations and their associated boundary conditions are transformed into coupled ordinary differential equations by utilizing an appropriate similarity transformation. Homotopy analysis method is utilized to evaluate the analytical solution in the form of infinite series. Also, the convergence region of the obtained solution is determined and plotted. The effects of pertaining parameters on radial, azimuthal and induced velocities of the fluid flow are presented graphically and discussed. Moreover comparisons have also been made with the previous results as a special case.

Touch Recognition Using a Passive Large Compliance Robotic Finger With Internal Sensors for Planar Applications

1999 ◽  
Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra
Keyword(s):  
Deflection Angle ◽  
Low Cost ◽  
Three Dimensional ◽  
Outer Edge ◽  
Degree Of Freedom ◽  
Two Dimensional ◽  
Outline Shape ◽  
Contact Points ◽  
Manipulator Arm ◽  
Two Degree Of Freedom

Abstract In this paper, a touch-sensing device consisting of a passive large compliance robotic finger with internal sensors, and algorithms for using this device for recognition applications are presented. These algorithms include recognition of the two-dimensional projected outline shape and dimensions of an object, and recognition of the three-dimensional convex outline height profiles of an object. The two-dimensional outline of an object is identified by tracing the object’s outer edge with the robotic finger and returning the XY coordinates of selected outline contact points and their tangent line directions. Recognition of the three-dimensional convex outline height profiles of an object is done by observing the change of the robotic finger deflection angle while moving the finger toward the object in contact. The feasibility of the device and the algorithms developed were successfully tested for planar applications by both analytical simulations and by experiments using a simple two-degree-of-freedom inverted joystick attached to the end of a planar manipulator arm. Simplicity, low cost, and easy implementation are some of the major benefits of using the proposed touch-sensing device.

Bifurcations in Twinkling Oscillators

2012 ◽  
Author(s):  
Smruti R. Panigrahi ◽  
Brian F. Feeny ◽  
Alejandro R. Diaz
Keyword(s):  
High Frequency ◽  
Energy Levels ◽  
Low Frequency ◽  
Degree Of Freedom ◽  
Nonlinear Structure ◽  
High Frequency Oscillations ◽  
Mass Chain ◽  
New Type ◽  
The Masses ◽  
Two Degree Of Freedom

We present the underlying dynamics of snap-through structures that exhibit twinkling. Twinkling occurs when the nonlinear structure is loaded slowly and the masses snap-through, converting the low frequency input to high frequency oscillations. We have studied a nonlinear spring-mass chain loaded by a quasistatic pull. The spring forces are assumed to be cubic with intervals of negative stiffness. Depending on the parameters, the system has equilibria at multiple energy levels. The normal form and the bifurcation behaviors for the single and two degree of freedom systems are studied in detail. A new type of bifurcation, which we refer to as a star bifurcation, has been observed for the symmetric two degree of freedom system, which is of codimension four for the undamped case, and codimension three or two for the damped case, depending on the form of the damping.

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