Estimation of radius and thickness of a thin spherical shell in water using the midfrequency enhancement of a short tone burst response

2005 ◽  
Vol 118 (4) ◽  
pp. 2147-2153 ◽  
Author(s):  
Wei Li ◽  
G. R. Liu ◽  
V. K. Varadan
Keyword(s):  
Spherical Shell ◽  
Tone Burst ◽  
Thin Spherical Shell

A fast approach for acoustic source localization on a thin spherical shell

2021 ◽  
pp. 147592172110419
Author(s):  
Zixian Zhou ◽  
Zhiwen Cui ◽  
Tribikram Kundu
Keyword(s):  
Velocity Profile ◽  
Spherical Shell ◽  
Source Localization ◽  
Pressure Vessels ◽  
Solution Technique ◽  
Acoustic Source ◽  
Spherical Shells ◽  
Fast Approach ◽  
Acoustic Source Localization ◽  
Thin Spherical Shell

Thin spherical shell structures are wildly used as pressure vessels in the industry because of their property of having equal in-plane normal stresses in all directions. Since very large pressure difference between the inside and outside of the wall exists, any formation of defects in the pressure vessel wall has a huge safety risk. Therefore, it is necessary to quickly locate the area where the defect maybe located in the early stage of defect formation and make repair on time. The conventional acoustic source localization techniques for spherical shells require either direction-dependent velocity profile knowledge or a large number of sensors to form an array. In this study, we propose a fast approach for acoustic source localization on thin isotropic and anisotropic spherical shells. A solution technique based on the time difference of arrival on a thin spherical shell without the prior knowledge of direction-dependent velocity profile is provided. With the help of “L”-shaped sensor clusters, only 6 sensors are required to quickly predict the acoustic source location for anisotropic spherical shells. For isotropic spherical shells, only 4 sensors are required. Simulation and experimental results show that this technique works well for both isotropic and anisotropic spherical shells.

Impulse response for backscattering by a thin spherical shell: Measurement and wave interpretation

1993 ◽  
Vol 94 (3) ◽  
pp. 1877-1877
Author(s):  
Gregory Kaduchak ◽  
Christopher S. Kwiatkowski ◽  
Philip L. Marston
Keyword(s):  
Spherical Shell ◽  
Impulse Response ◽  
Thin Spherical Shell

scholarly journals Magnetic Helicity and the Solar Dynamo

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 811
Author(s):  
John V. Shebalin
Keyword(s):  
Statistical Mechanics ◽  
Spherical Shell ◽  
Turbulent Energy ◽  
Self Organization ◽  
Magnetic Helicity ◽  
Mhd Turbulence ◽  
Dynamo Action ◽  
Inherent Property ◽  
Thin Spherical Shell ◽  
Macroscopic Parameters

Solar magnetism is believed to originate through dynamo action in the tachocline. Statistical mechanics, in turn, tells us that dynamo action is an inherent property of magnetohydrodynamic (MHD) turbulence, depending essentially on magnetic helicity. Here, we model the tachocline as a rotating, thin spherical shell containing MHD turbulence. Using this model, we find an expression for the entropy and from this develop the thermodynamics of MHD turbulence. This allows us to introduce the macroscopic parameters that affect magnetic self-organization and dynamo action, parameters that include magnetic helicity, as well as tachocline thickness and turbulent energy.

scholarly journals Nonlinear Modeling of the Solar Tachocline

2001 ◽  
Vol 203 ◽  
pp. 202-204
Author(s):  
M. S. Miesch
Keyword(s):  
Spherical Shell ◽  
Nonlinear Modeling ◽  
Realistic Model ◽  
Stratified Turbulence ◽  
Thin Spherical Shell

As a first step toward a more realistic model of the solar tachocline, we report simulations of rotating, stably-stratified turbulence in a thin spherical shell.

Buckling load prediction of an externally pressurized thin spherical shell with localized imperfections

2018 ◽  
Vol 24 (3) ◽  
pp. 653-667 ◽  
Author(s):  
Alexander Evkin ◽  
Maksym Kolesnikov ◽  
Olga Lykhachova
Keyword(s):  
Spherical Shell ◽  
Nonlinear Behavior ◽  
Buckling Load ◽  
Asymptotic Result ◽  
The Finite Element Method ◽  
Load Prediction ◽  
Deflection Amplitude ◽  
Asymptotic Formulae ◽  
Post Buckling ◽  
Thin Spherical Shell

A simple formula for buckling load was derived from the asymptotic analysis of nonlinear behavior of a thin spherical shell. Firstly, two asymptotic cases were studied: the initial post-buckling regime of a perfect structure with small (compared to shell thickness) deflections and equilibrium states with large deflections. Two asymptotic formulae were jointed to obtain the solution for the entire range of deflection amplitude. Then the solution was modified for an imperfect shell. Initial deflections were introduced by only one parameter: the slope of the load–deflection diagram at small pressure. This minimal information was enough to predict the buckling load of the structure with localized imperfections. The suggested asymptotic result was validated by the finite element method and by comparison with experimental data.

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