The three–dimensional incompressible viscous Boussinesq equations, under the assumption of hydrostatic balance, govern the large scale dynamics of atmospheric and oceanic motion, and are commonly called the primitive equations. To overcome the turbulence mixing a partial vertical diffusion is usually added to the temperature advection (or density stratification) equation. In this paper we prove...

In quantum theory Hamilton operators with spininteractions have a long history [1 – 5]. Triple spin interaction have been studied by several authors [6 – 19]. Iglói [6] investigated an Ising model with three-spin interaction by finite-size scaling and applying free boundary conditions. Vanderzande and Iglói [7] studied the critical behaviour and logarithmic corrections of a quantum model with t...

This paper proves sharp inequalities for the frequencies of vibration of strings and cylindrical membranes, under either fixed or fixed-free boundary conditions. We establish such inequalities also on the "generalized" cylinder, which is the cross-product of an interval with a homogeneous Riemannian manifold. The goal is to better understand the effect that inhomogeneities in the mass distribut...

Controllability properties of a partial di erential equation (PDE) model describing a thermoelastic plate are studied. The PDE is comprised of a Kircho plate equation coupled to a heat equation on a bounded domain, with the coupling taking place on the interior and boundary of the domain. The coupling in this PDE is parameterized by > 0. Boundary control is exerted through the (two) free bounda...

Experimental investigation of flow development within a rectangular 90o curved diffusing C-duct of low aspect ratio and area ratio of 2 was carried out and the threedimensional computational results are then compared with the experimental results for numerical validation. All measurements were made in a turbulent flow regime (Re = 2.35x10 5 ), based on the duct inlet hydraulic diameter (dh = 0....

the study of wave and its propagation on the water surface is among significant phenomena in designing quay, marine and water structures. therefore, in order to design structures which are exposed to direct wave forces, it is necessary to study and simulate water surface height and the wave forces on the structures body in different boundary conditions. in this study, the propagation of static ...

To facilitate the research of mobile robot based odor source localization (OSL) and evaluate different strategies for the OSL, numerical simulation of odor plume in indoor ventilated environments is addressed. On the basis of the FLUENT software package, the 3-D wind field of an indoor ventilated environment is calculated using the Reynolds average approach, where the real wind velocity measure...

A one-dimensional leakage flow model for two-phase ammonia-water twin screw compressors is presented. The model takes into account viscous and acceleration forces and is based on three conservation equations and on the equation of state for homogenous NHiH20 mixture. The governing equations are solved with a finite difference method. Numerical shooting is used to find such inlet flow velocity a...