The Capacitance of a Circular Annulus

1951 ◽  
Vol 22 (12) ◽  
pp. 1499-1501 ◽  
Author(s):  
W. R. Smythe
Keyword(s):  
Circular Annulus

The Aharonov–Bohm effect and its stationary scattering states from the flat circular annulus U(1) holonomy

2014 ◽  
Vol 11 (10) ◽  
pp. 1450084
Author(s):  
Gabriel Y. H. Avossevou ◽  
Bernadin D. Ahounou
Keyword(s):  
Scattering Problem ◽  
Heisenberg Algebra ◽  
Scattering Data ◽  
Gauge Potential ◽  
Circular Annulus ◽  
Topological Quantum ◽  
Vector Gauge ◽  
Simply Connected ◽  
Aharonov Bohm ◽  
Stationary Scattering

In this paper we study the stationary scattering problem of the Aharonov–Bohm (AB) effect. To achieve this goal we construct a Hamiltonian from the most general representations of the Heisenberg algebra. Such representations are defined on a non-simply-connected manifold which we set as the flat circular annulus. By means of the von Neumann's self-adjoint extensions formalism, the scattering data are then provided. No solenoid is considered in this paper. The corresponding Hamiltonian is based on a topological quantum degree of freedom inherent in such representations. This variable stands for the magnetic vector gauge potential at quantum level. Our outcomes confirm the topological nature of this effect.

scholarly journals Inertial waves and mean velocity profiles in a rotating pipe and a circular annulus with axial flow

2015 ◽  
Vol 91 (1) ◽  
Author(s):  
Yantao Yang ◽  
Rodolfo Ostilla-Mónico ◽  
Jiezhi Wu ◽  
Paolo Orlandi
Keyword(s):  
Axial Flow ◽  
Velocity Profiles ◽  
Inertial Waves ◽  
Mean Velocity ◽  
Circular Annulus

Viscous Flow in an Annulus With a Sector Cavity

1982 ◽  
Vol 104 (4) ◽  
pp. 500-504 ◽  
Author(s):  
V. O’Brien
Keyword(s):  
Biharmonic Equation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Cavity Flow ◽  
Three Dimensional Flow ◽  
Circular Annulus ◽  
Dimensional Interaction ◽  
Laminar Mixing ◽  
Flow Through ◽  
Finite Difference Solution

The two-dimensional interaction of a circular shear flow and a sector cavity flow is predicted by finite-difference solution of the governing biharmonic equation for steady Stokes planar flow. The location of the dividing streamline is a function of geometry, lying perhaps wholly within the cavity or bulging up into the circular annulus. Also pressure-driven axial flow through the annular configuration is predicted by numerical solution of the governing Poisson equation. The results can be combined with the planar solution to describe a steady three-dimensional flow field which will enhance laminar mixing.

scholarly journals Effect of wall-slip on natural convection in a circular annulus

2021 ◽  
Vol 1132 (1) ◽  
pp. 012042
Author(s):  
Gautham S. Nair ◽  
R. Harikrishna ◽  
Damu Murali ◽  
S. Ajith Kumar
Keyword(s):  
Natural Convection ◽  
Wall Slip ◽  
Circular Annulus

Cementing Irregular Horizontal Wellbores

2021 ◽  
Author(s):  
Alondra Renteria ◽  
Parisa Sarmadi ◽  
Ian Frigaard
Keyword(s):  
3D Model ◽  
Secondary Flows ◽  
Positive Density ◽  
Drilling Mud ◽  
Horizontal Section ◽  
Two Fluids ◽  
Circular Annulus ◽  
Primary Cementing ◽  
Horizontal Wellbores ◽  
Averaged Model

Abstract In this work, we study the effect of borehole irregularities during primary cementing of a horizontal section of well. We use a simplified 2D gap-averaged model to compute the displacement of a drilling mud by a spacer within an elliptical annulus that represents an oval irregularity. We also present a series of 3D numerical simulations using a Volume of Fluid method to capture the interface between the fluids. The 3D model allows us to study the effects of more local irregularities such as wall roughness that can be imported from a caliper log. The dynamics of the displacement of two fluids in a horizontal uniform circular annulus is governed by buoyancy, eccentricity and the rheology of the fluids. A positive density difference combined with a slow mean pumping speed promotes slumping of the second fluid towards the bottom of the annulus. Nevertheless, high eccentricity values (e = 1-standoff) are common due to the weight of the casing pulling downwards, opposing the buoyancy force. Finally, the rheology of the fluids is relevant to determine the presence of un-displaced layers of mud, e.g. at the walls. The same competition described above holds true in the elliptical annulus. Results from the 2D gap-averaged model suggest that the elliptical shape incorporates an additional way of altering the velocity field around it. The effect is more evident when orienting the largest radius of the elliptical annulus at different angles. Results from 3D simulations show that the interface follows irregularities and the local roughness can improve the displacement by inducing secondary flows. However, enlargements result in poor displacement.

Guided Circumferential Waves in a Circular Annulus

1998 ◽  
Vol 65 (2) ◽  
pp. 424-430 ◽  
Author(s):  
Guoli Liu ◽  
Jianmin Qu
Keyword(s):  
Frequency Dispersion ◽  
Radius Of Curvature ◽  
Harmonic Waves ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Circular Annulus ◽  
Time Harmonic ◽  
Steady State Time ◽  
Wave Phenomena ◽  
Circumferential Waves

A two-dimensional circular annulus is considered in this paper as a waveguide. The guided steady-state time-harmonic waves propagating in the circumferential direction are studied. It is found that the guided circumferential waves are dispersive. The dispersion equation is derived analytically and numerical examples are presented for the frequency dispersion curves. The displacement profiles across the wall thickness of the annulus are also obtained for the first five propagating modes. In addition, the analogy between a flat plate and an annulus in the asymptotic limit of infinite radius of curvature is discussed to reveal some interesting wave phenomena intrinsic to curved waveguides.

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