Thin superconductors: the stream function method

2021 ◽  
Author(s):  
Antonio Badía-Majós
Keyword(s):  
Stream Function ◽  
Function Method

scholarly journals ESTIMATION OF WATER PARTICLE VELOCITIES OF SHALLOW WATER WAVES BY A MODIFIED TRANSFER FUNCTION METHOD

1986 ◽  
Vol 1 (20) ◽  
pp. 33 ◽  
Author(s):  
Hirofumi Koyama ◽  
Koichiro Iwata
Keyword(s):  
Transfer Function ◽  
Shallow Water ◽  
Approximate Method ◽  
Stream Function ◽  
Water Waves ◽  
Function Method ◽  
Finite Amplitude ◽  
Water Particle ◽  
Irregular Wave ◽  
Particle Velocities

This paper Is intended to propose a simple, yet highly reliable approximate method which uses a modified transfer function in order to evaluate the water particle velocity of finite amplitude waves at shallow water depth in regular and irregular wave environments. Using Dean's stream function theory, the linear function is modified so as to include the nonlinear effect of finite amplitude wave. The approximate method proposed here employs the modified transfer function. Laboratory experiments have been carried out to examine the validity of the proposed method. The approximate method is shown to estimate well the experimental values, as accurately as Dean's stream function method, although its calculation procedure is much simpler than that of Dean's method.

scholarly journals Validation of the stream function method used for reconstruction of experimental ionospheric convection patterns

2000 ◽  
Vol 18 (4) ◽  
pp. 454-460
Author(s):  
P.L. Israelevich ◽  
V. O. Papitashvili ◽  
A. I. Ershkovich
Keyword(s):  
Boundary Value Problem ◽  
Boundary Conditions ◽  
Stream Function ◽  
Electric Fields ◽  
Electric Potential ◽  
Potential Distribution ◽  
Function Method ◽  
Polar Cap ◽  
Ionospheric Convection ◽  
Convection Patterns

Abstract. In this study we test a stream function method suggested by Israelevich and Ershkovich for instantaneous reconstruction of global, high-latitude ionospheric convection patterns from a limited set of experimental observations, namely, from the electric field or ion drift velocity vector measurements taken along two polar satellite orbits only. These two satellite passes subdivide the polar cap into several adjacent areas. Measured electric fields or ion drifts can be considered as boundary conditions (together with the zero electric potential condition at the low-latitude boundary) for those areas, and the entire ionospheric convection pattern can be reconstructed as a solution of the boundary value problem for the stream function without any preliminary information on ionospheric conductivities. In order to validate the stream function method, we utilized the IZMIRAN electrodynamic model (IZMEM) recently calibrated by the DMSP ionospheric electrostatic potential observations. For the sake of simplicity, we took the modeled electric fields along the noon-midnight and dawn-dusk meridians as the boundary conditions. Then, the solution(s) of the boundary value problem (i.e., a reconstructed potential distribution over the entire polar region) is compared with the original IZMEM/DMSP electric potential distribution(s), as well as with the various cross cuts of the polar cap. It is found that reconstructed convection patterns are in good agreement with the original modelled patterns in both the northern and southern polar caps. The analysis is carried out for the winter and summer conditions, as well as for a number of configurations of the interplanetary magnetic field.Key words: Ionosphere (electric fields and currents; plasma convection; modelling and forecasting)

FEM Analysis during Extrusion of Round-To-Pentagonal Sections through Converging Dies

2012 ◽  
Vol 500 ◽  
pp. 410-413
Author(s):  
Akshaya Kumar Rout ◽  
Kali Pada Maity
Keyword(s):  
Velocity Field ◽  
Stream Function ◽  
Function Method ◽  
Fem Analysis ◽  
Extrusion Process ◽  
Extrusion Pressure ◽  
Upper Bound Method ◽  
Die Profile ◽  
Deform 3D ◽  
Dual Stream Function

The linearly converging die plays a significant role in the extrusion process of section products in terms of reduction in extrusion load and improvement of product quality. With the help of upper bound method based on dual stream function method. Very few investigations have been reported when product and billet geometry are dissimilar using linear converging die. Dual stream function method is incapable of predicting kinematically admissible velocity field in the above case, SERR technique (Spatial Elementary Rigid Region) is the only alternative. In the present investigation, a reformulated SERR technique has been used to determine non-dimensional extrusion pressure and optimum die profile both for frictionless and friction conditions. SERR technique based on discontinuous velocity field is applicable for this case. In the present investigation, non-dimensional extrusion pressure and optimum die length has been determined for extrusion of pentagonal from round billet and the results are compared with the FEA results by using DEFORM 3D.

Force Stream Function Method Applied to Classical Griffith’s Crack Problem

2007 ◽  
Vol 129 (8) ◽  
pp. 1080-1082
Author(s):  
Xiang Wu ◽  
Joseph Genin
Keyword(s):  
Stress Analysis ◽  
Stream Function ◽  
Function Method ◽  
General Relation ◽  
Crack Problem ◽  
Numerical Results ◽  
Analysis Procedure ◽  
New Method ◽  
Fluid Stream ◽  
Linear Fracture

In a previous paper (Wu, X., and Genin, J., 2003, J. Strain Anal. Eng. Des., 38(2), pp. 181–185), we presented a new stress analysis procedure, the force stream function method. It established a general relationship between a fluid stream function and a force stream function through pure elasticity examples. Here, we expand its applications to the field of linear fracture. A brief review of the new method is provided at the paper’s beginning. When applied to the classical Griffith’s crack problem, the corresponding fluid stream function of a flow past a normal plate is conveniently used as an analog for the crack problem. Numerical results are employed to verify the general relation in this particular case. The significance of the new force stream function method and some difficulties of its applications are discussed in the paper’s conclusion.

Slab analysis based on stream function method in chamfer edge rolling of ultra-heavy plate

2016 ◽  
Vol 231 (7) ◽  
pp. 1237-1251
Author(s):  
JG Ding ◽  
HY Wang ◽  
DH Zhang ◽  
DW Zhao
Keyword(s):  
Velocity Field ◽  
Stream Function ◽  
Function Method ◽  
Rolling Force ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Total Power ◽  
Shape Coefficient ◽  
Heavy Plate ◽  
Dog Bone

In this paper, three-dimensional velocity field is proposed by means of stream function method with bisecting yield criterion in chamfer edge rolling of ultra-heavy plate. Parabolic dog-bone shape function is derived so as to obtain velocity field with fixed angle of chamfer edge by stream function method, dog-bone shape coefficient η can be derived from volume invariant condition, and then the plastic deformation power, shear power as well as friction power are obtained respectively with the bisecting yield criterion. Summing up the power contributions, total power functional is presented, from which minimum value can be obtained by searching method, and vertical rolling force and torque are also finally obtained. The predictions of roll force and torque are compared with different angles of chamfer edge as well as different plate thicknesses. The results are shown to be in a very good agreement with the analytical and experimental results.

Simulation of Rarefied Gas Flow in Microchannel Based on Vorticity-Stream Function Method

2007 ◽  
Author(s):  
Xueyong Wei ◽  
Mike C. L. Ward ◽  
Dejiang Lu ◽  
Zhuangde Jiang
Keyword(s):  
Stream Function ◽  
Function Method ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Taylor Series Expansion ◽  
Accommodation Coefficient ◽  
Parallel Plates ◽  
Slip Boundary ◽  
Tangential Momentum ◽  
New Formula

Vorticity-stream function method is successfully used to solve an incompressible gas flow in the parallel-plates micro-channel. A new formula in finite difference scheme is developed to describe the boundary vorticity based on the slip boundary theory and Taylor series expansion. Results show that the boundary vorticity are not only influenced by the Knudsen number (Kn) but also influenced by the tangential momentum accommodation coefficient (TMAC).

scholarly journals ON THE RELATION BETWEEN CHANGES IN INTEGRAL QUANTITIES OF SHOALING WAVES AND BREAKING INCEPTION

1982 ◽  
Vol 1 (18) ◽  
pp. 2
Author(s):  
Takeshi Yasuda ◽  
Shintaro Goto ◽  
Yoshito Ysuchiya
Keyword(s):  
Conservation Laws ◽  
Stream Function ◽  
Function Method ◽  
Breaking Waves ◽  
Variable Coefficients ◽  
Shoaling Waves ◽  
Wave Profiles ◽  
Internal Properties ◽  
Particle Velocities ◽  
The Waves

This paper describes a mechanism of breaking waves over sloping bottoms in terms of changes in integral quantities of the waves. Systematic computations are made of wave profiles of shoaling waves up to the numerical unstable points by using the K-dV equation with variable coefficients and internal properties such as horizontal and vertical water particle velocities by a stream function method satisfying the conservation laws of mass and energy. Applicability of the numerical results is examined and a relation between numerical unstable points and actual breaker points is found. Characteristics of the integral quantities of shoaling waves are investigated in relation to the existence of the extremum of the energy of the shoaling waves and their breaking inception.

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