We study global non-axisymmetric oscillation modes trapped near the inner boundary of an accretion disc. Observations indicate that some of the quasi-periodic oscillations (QPOs) observed in the luminosities of accreting compact objects (neutron stars, black holes and white dwarfs) are produced in the inner-most regions of accretion discs or boundary layers. Two simple models are considered in ...

Small deformations of a viscoelastic body are considered through the linear Maxwell and Kelvin-Voigt models in the quasi-static equilibrium. A robust mixed finite element method, enforcing the symmetry of the stress tensor weakly, is proposed for these equations on simplicial tessellations in two and three dimensions. A priori error estimates are derived and numerical experiments presented. The...

In this paper, the classic Kelvin-Voigt model coupled thermo-viscoelasticity model of hollow and solid spheres under radial symmetric loading condition is considered. A full analytical method is used and an exact unique solution of the classic coupled equations is presented. The thermal and mechanical boundary conditions, the body force, and the heat source are considered in the most general fo...

Time-integration for lumped parameter systems obeying implicit Bingham-Kelvin constitutive models is studied. The governing system of equations describing the lumped parameter system is a non-linear differential-algebraic equation and needs to be solved numerically. The response of this system is non-smooth and the kinematic variables can not be written in terms of the dynamic variables, explic...

In this work, three types of vehicle suspensions were considered and modeled as follows: oil damper mounted in parallel with a compression helical spring, for which a Kelvin-Voigt model, consisted of a dashpot and an elastic element connected in parallel is considered; colloidal damper without attached compression helical spring, for which a Maxwell model, consisted of a dashpot and an elastic ...

abstract prediction of input flow into water resources is regarded as one of the most important issues in optimum planning and management in producing electro-water energy and optimum allocation of water into different consumption sources. different parameters affect on input discharge into dams. climate variables including temperature and rainfall have the most effect on input runoff rate to w...

In this study, the general partial differential equation of unsteady groundwater flow through non-homogeneous and anisotropic aquifer was solved by the fully implicit finite difference method with control volume approach. The calibration of permeability and storage coefficients as model parameters was performed by a transformation technique and application of Powell's non-linear optimization me...

In this paper, we describe how we can precisely produce complex and various dynamic morphological features such as structured and chaotic features which occur in sand pilings (piles, avalanches, internal collapses, arches) , in flowing fluids (laminar flowing, Kelvin-Helmholtz and Von Karmann eddies), and in cohesive pastes (twist-and-turn oozing and packing) using only a single unified model, ...

The Simple Ocean Data Assimilation (SODA) reanalysis (1958–2001) is used to investigate the decadal variability in the equatorial thermocline in the Pacific.Whereas the thermocline depth exhibits weak variation at decadal time scales, the temperature change in the vicinity of the thermocline in the western Pacific is significant and has a vertical scale of;150 m. Based on a modal decomposition ...