Recently Shukurov et al [Phys Rev E 72, 025302 (2008)], made use of nonorthogonal curvilinear coordinate system on a dynamo Moebius strip flow, to investigate the effect of stretching by a turbulent liquid sodium flow. In plasma physics, Chui and Moffatt [Proc Roy Soc A 451,609,(1995)] (CM), considered non-orthogonal coordinates to investigate knotted magnetic flux tube Riemann metric. Here it ...

In this paper we augment the wave-averaged mean field equations commonly used to describe wave set-up and wave-induced mean currents in the near-shore zone, with an empirical sediment flux law depending only on the wave-induced mean current and mean total depth. This model allows the bottom to evolve slowly in time, and is used to examine how sediment transport affects wave set-up in the surf z...

We study the conductance of mesoscopic graphene rings in the presence of a perpendicular magnetic field by means of numerical calculations based on a tightbinding model. First, we consider the magnetoconductance of such rings and observe the Aharonov-Bohm effect. We investigate different regimes of the magnetic flux up to the quantum Hall regime, where the Aharonov-Bohm oscillations are suppres...

SUMMARY We present a new nonlinear monotone finite volume method for diffusion and convection-diffusion equations and its application to two-phase black oil models. We consider full anisotropic discontinuous diffusion/permeability tensors and discontinuous velocity fields on conformal polyhedral meshes. The approximation of the diffusive flux uses the nonlinear two-point stencil which reduces t...

Some of the morbidity associated with chronic hemodialysis is thought to result from retention of large molecular weight solutes that are poorly removed by diffusion in conventional hemodialysis. Hemodiafiltration combines convective and diffusive solute removal in a single therapy. The hypothesis that hemodiafiltration provides better solute removal than high-flux hemodialysis was tested in a ...

We use a flux transport model to simulate the evolution of the Sun’s total and open magnetic flux over the last 26 solar cycles (1713–1996). Polar field reversals are maintained by varying the meridional flow speed between 11 and 20 m s , with the poleward-directed surface flow being slower during low-amplitude cycles. If the strengths of the active regions are fixed but their numbers are taken...

A = Jacobian matrix a = speed of sound, m∕s C = source term vector E = total energy, J∕kg e = internal energy vector, J∕kg F = inviscid flux tensor Fd = diffusive flux tensor Fo = Forchheimer number G = flux tensor, F − Fd − uU h = enthalpy, J∕kg h = species enthalpy vector, J∕kg hr = recovery enthalpy, J∕kg I = identity matrix J = directional species diffusion flux tensor, kg∕m K = permeabilit...

We consider the development of Implicit-Explicit (IMEX) RungeKutta schemes for hyperbolic and kinetic equations in the diffusion limit. In such regime the system relaxes towards a parabolic diffusion equation and it is desirable to have a method that is able to capture the asymptotic behavior with an implicit treatment of limiting diffusive terms. To this goal we reformulate the problem by prop...

This paper proposes an efficient splitting algorithm to solve coupled liquid gas Darcy and free gas flows at the interface between a porous medium and a free-flow domain. This model is compared to the reduced model introduced in [6] using a 1D approximation of the gas free flow. For that purpose, the gas molar fraction diffusive flux at the interface in the free-flow domain is approximated by a...

Thermal accommodation coefficient, one of the fundamental parameters in rarefied gas dynamics, is usually introduced to account for the fraction of incident molecules interacting with solid surface in a diffusive manner. In the present study, the effects of thermal accommodation on the unsteady one-dimensional micro-flow are examined, when the oscillating flow input is applied, by employing the...