G R - Q C - 9 40 50 35 Shear - free , Irrotational , Geodesic , Anisotropic Fluid

Isotropic singularities in shear-free perfect fluid cosmologies

We investigate barotropic perfect fluid cosmologies which admit an isotropic singularity. From the General Vorticity Result of Scott, it is known that these cosmologies must be irrotational. In this paper we prove, using two different methods, that if we make the additional assumption that the perfect fluid is shear-free, then the fluid flow must be geodesic. This then implies that the only she...

Energy equation for irrotational theories of gas-liquid flow:: viscous potential flow (VPF), viscous potential flow with pressure correction (VCVPF), dissipation method (DM)

The effects of viscosity on the irrotational motions of spherical cap bubble, Taylor bubbles in round tubes, Rayleigh-Taylor and Kelvin-Helmholtz instability described in previous chapters were obtained by evaluating the viscous normal stress on potential flow. In gas-liquid flows, the viscous normal stress does not vanish and it can be evaluated on the potential. It can be said that in the cas...

Pressure corrections for potential flow analysis of capillary instability of viscous fluids

Funada & Joseph (2002) analyzed capillary instability assuming that the flow is irrotational but the fluids are viscous (viscous potential flow, VPF). They compared their results with the exact normal mode solution of the linearized Navier-Stokes equations (fully viscous flow, FVF) and with the irrotational flow of inviscid fluids (inviscid potential flow, IPF). They showed that the growth rate...

Transient free convective flow of a micropolar fluid between two vertical walls

Classical big-bounce cosmology: dynamical analysis of a homogeneous and irrotational Weyssenhoff fluid

A dynamical analysis of an effective homogeneous and irrotational Weyssenhoff fluid in general relativity is performed using the 1 + 3 covariant approach that enables the dynamics of the fluid to be determined without assuming any particular form for the space-time metric. The spin contributions to the field equations produce a bounce that averts an initial singularity, provided that the spin d...