Controllable vortex chirality switching on spherical shells

Controllable vortex chirality switching on spherical shells

Nematic textures in spherical shells.

The equilibrium texture of nematic shells is studied as a function of their thickness. For ultrathin shells the ground state has four short 1/2 disclination lines but, as the thickness of the film increases, a three-dimensional escaped configuration composed of two pairs of half-hedgehogs becomes energetically favorable. We derive an exact solution for the nematic ground state in the one Frank ...

Buckling of Spherical Shells Revisited

A study is presented of the post-buckling behavior and imperfection-sensitivity of complete spherical shells subject to uniform external pressure. The study builds on and extends the major contribution to spherical shell buckling by W.T. Koiter in the 1960’s. Numerical results are presented for the axisymmetric large deflection behavior of perfect spheres followed by an extensive analysis of th...

On a transitional and turbulent natural convection in spherical shells

Laminar and turbulent natural convection inside concentric spherical shells with isothermal cold and hot boundaries is numerically investigated up to Rayleigh number values Ra 6 10 and Pr = 0.71. The study utilizes direct numerical simulation (DNS), large eddy simulation (LES) and Reynolds averaged Navier– Stokes (RANS) approaches for investigation of the laminar, transitional and fully develop...

A fully discretised filtered polynomial approximation on spherical shells

A fully implementable filtered polynomial approximation on spherical shells is considered. The method proposed is a quadrature-based version of a filtered polynomial approximation. The radial direction and the angular direction of the shells are treated separately with constructive filtered polynomial approximation. The approximation error with respect to the supremum norm is shown to decay alg...