We consider the point indentation of a pressurized, spherical elastic shell. Previously it was shown that such shells wrinkle once the indentation reaches a threshold value. Here, we study the behaviour of this system beyond the onset of instability. We show that rather than simply approaching the classical “mirror-buckled” shape, the wrinkled shell approaches a new, universal shape that reflec...

A fully three-dimensional, nonlinear, time-dependent spherical interface dynamo is investigated using a finite-element method based on the three-dimensional tetrahedralization of the spherical system. The spherical interface dynamo model consists of four zones: an electrically conducting and uniformly rotating core, a thin differentially rotating tachocline, a uniformly rotating turbulent conve...

We perform for the first time a 3D hydrodynamics simulation of evolution last minutes pre-collapse oxygen shell fast-rotating massive star. This star has an initial mass 38 M$_\odot$, metallicity $\sim$1/50 Z$_\odot$, rotational velocity 600 km s$^{-1}$, and experiences chemically homogeneous evolution. It silicon- oxygen-rich (Si/O) convective layer at (4.7-17)$\times 10^{8}$ cm, where oxygen-...

We present near-infrared polarimetric images of the dusty circumstellar envelope (CSE) of IRAS 19306+1407, acquired at the United Kingdom Infrared Telescope (UKIRT) using the UKIRT 1-5 μm Imager Spectrometer (UIST) in conjunction with the half-waveplate module IRPOL2. We present additional 450 and 850 μm photometry obtained with the Sub-mm Common User Bolometer Array (SCUBA) at the James Clerk ...

Thin shell torispherical pressure vessel heads are known to exhibit complex elasticplastic deformation and buckling behaviour under static pressure. In pressure vessel Design by Analysis, the designer is required to assess both of these behaviour modes when specifying the allowable static load. The EN and ASME Boiler and Pressure Vessel Codes permit the use of inelastic analysis in design by an...

We consider the dynamics of axial velocity and of scalar transport in the stretched-spiral vortex model of turbulent fine scales. A large-time asymptotic solution to the scalar advection-diffusion equation, with an azimuthal swirling velocity field provided by the stretched spiral vortex, is used together with appropriate stretching transformations to determine the evolution of both the axial v...

in this paper, the axisymmetric corrugated diaphragm using finite element method will be discussed, so that half of these diaphragms’ cross sections and later the applied pressure will be considered. following this, using the consequent equations and visual basic software, a computer program will be provided which receives the diaphragms’ particulars such as diameter, thickness, pressure and th...

This paper presents a comparison of numerical methods for the modelling of pile driving noise in the near field of the pile. The numerical models considered consist of (1) an axisymmetric time domain finite difference method (FDM), developed by the Centre for Marine Science and Technology in the Matlab programming language, and (2) an axisymmetric time domain finite element method (FEM), which ...

This paper presents and compares three analytical methods for calculating low frequency band gap boundaries in doubly periodic arrays of resonating thin elastic shells. It is shown that both Foldy-type equations (derived with lattice sum expansions in the vicinity of its poles) and a self-consistent scheme could be used to predict boundaries of low-frequency (below the first Bragg band gap) ban...

Thin shell torispherical pressure vessel heads are known to exhibit complex elasticplastic deformation and buckling behaviour under static pressure. In pressure vessel Design by Analysis, the designer is required to assess both of these behaviour modes when specifying the allowable static load. The EN and ASME Boiler and Pressure Vessel Codes permit the use of inelastic analysis in design by an...