We investigate clogging in depth filtration, in which a dirty fluid is ‘‘cleaned’’ by the trapping of dirt particles within the pore space during flow through a porous medium. This leads to a self-generated gradient percolation process that exhibits a power-law distribution for the density of trapped particles at downstream distance x from the input. To achieve a nonpathological clogging ~perco...

SUMMARY An immersed finite element Fluid-Structure Interaction (FSI) algorithm with an anisotropic remeshing strategy for thin rigid structures is presented in two-dimensions. The algorithm consists in remeshing only the fluid elements that are cut by the solid such that they fit the solid geometry. This approach allows to keep the initially provided fluid mesh vertexes fixed during the whole s...

The possibility of strange stars mixed with dark energy to be one of candidates for dark energy stars is the main issue of the present study. Our investigation shows that quark matter is acting as dark energy after certain yet unknown critical condition inside the quark stars. Our proposed model reveals that strange stars mixed with dark energy feature not only a physically acceptable stable mo...

We discuss the averaging problem in general relativity, using the form of the macroscopic gravity equations in the case of spherical symmetry in volume preserving coordinates. In particular, we calculate the form of the correlation tensor under some reasonable assumptions on the form for the inhomogeneous gravitational field and matter distribution. On cosmological scales, the correlation tenso...

The full set of equations governing the structure and the evolution of self–gravitating spherically symmetric dissipative fluids with anisotropic stresses, is written down in terms of five scalar quantities obtained from the orthogonal splitting of the Riemann tensor, in the context of general relativity. It is shown that these scalars are directly related to fundamental properties of the fluid...

The motion of magnetic nanowires can be manipulated by a magnetic field in liquids so that their distribution, alignment and orientation can be effectively controlled. The small dimensions of nanoscale entities result in an extremely low Reynolds number, and a steady state Stokes flow approximation was adopted to analyze the nanowire motion under the influences of applied field. The effects of ...

On the ground of manufacturing, sheet metal parts play a key role as they cover about half of the production processes. Sheet metals are commonly obtained from rolling and forming processes which causes misalignment of micro structure resulting obvious anisotropic characteristics and micro cracks. Presence of micro cracks poses serious attention, when stresses at the tip reach to the critical v...

We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations and physically implemented with anisotropic porous media permeable to the flow of fluids. In two situations-for an impermeable object placed either in a free-flowing fluid or in a fluid-filled ...

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state (p ∝ ρ) in a spatially flat (Bianchi type I) cosmology. These models approach an isotropic, general relativistic solution as the expansion becomes dominated by the barot...

A Bianchi type -I metric of Kasner form is considered, when the space is filled with a viscous fluid. Whereas an ideal (nonviscous) fluid permits the Kasner metric to be anisotropic provided that the fluid satisfies the Zel’dovich equation of state, the viscous fluid does not permit the Kasner metric to be anisotropic at all. In the latter case, we calculate the Kasner (isotropic) metric expres...