Capillary instability of a viscous fluid cylinder of diameter D surrounded by another fluid is determined by a Reynolds number J = V D `= `, a viscosity ratio m = a= ` and a density ratio ` = a= `. Here V = = ` is the capillary collapse velocity based on the more viscous liquid which may be inside or outside the fluid cylinder. Results of linearized analysis based on potential flow of a viscous...

Capillary instability of a liquid cylinder immersed in another liquid is analyzed based on potential flow solutions. The growth rate of the instability is obtained by considering the normal stress balance at the interface. We derive a viscous correction of the irrotational pressure which presumably arises from a boundary layer induced by the discontinuity of the tangential velocity and shear st...

Bulk viscosity suppresses elliptic flow v2, as does shear viscosity. It can thus not be neglected when extracting the shear viscosity from elliptic flow data. We here explore uncertainties in the bulk viscous contribution to viscous v2 suppression that arise from presently uncontrolled uncertainties in the initial value of the bulk viscous pressure and its microscopic relaxation time.

entropy generation in an unsteady hydromagnetic couette flow of a viscous incompressible electrically conducting fluid between two infinite horizontal parallel plates in a rotating system have been analyzed. both the lower and upper plates of the channel are subjected to asymmetric convective heat exchange with the ambient following the newton's law of cooling. a numerical solution for governin...

This paper extends the gas-kinetic BGK-NS scheme to an adaptive grid for the viscous flow simulations. The grid movement and adaptation is controlled by a monitor function which may depend on velocity gradient or other flow variables, such as density or pressure. For the viscous flow computation, the use of adaptive mesh much improves the efficiency and accuracy of the method in comparison with...

In this paper, we study flow through thin porous media as in, e.g. seals or fractures. It is often useful to know the permeability of such systems. In the context of incompressible and iso-viscous fluids, the permeability is the constant of proportionality relating the total flow through the media to the pressure drop. In this work, we show that it is also relevant to define a constant permeabi...

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...

Potential flow over rotating cylinder is usually solved by the singularity method. However,in this paper a mathematical solution is presented for this problem by direct solution of the Laplace’sequation. Flow over the cylinder was considered non-viscous. Neumann and Dirichlet boundaryconditions were used on the solid surfaces and in the infinity, respectively. Because of non-viscous flow,the La...