Band 20, Heft 5

A numerical model of passive scalar dynamics in turbulent wakes of bodies of revolution in a linearly stratified medium is constructed. To describe the flow we use a three-dimensional parabolized system of equations of motion, continuity, incompressibility, turbulent energy transport, dissipation rate, averaged concentration and dispersion of passive scalar concentration fluctuations. Computational results demonstrate the behaviour of passive scalar characteristics both for momentumless wake and in the wake behind a towed body.

The present paper discusses the results of the numerical simulation of the process of surface wave generation by a moving underwater landslide. The computational algorithms are based on finite difference schemes for shallow water equations of different orders of hydrodynamic approximation and equations for potential ideal fluid flows with a free boundary. The dependence of the parameters of generated waves on the law of motion of the migrating bottom fragment is studied.

An elliptic method based on comprehensive monitor metrics is developed for generating vector field-aligned grids. Some results of numerical experiments are demonstrated.

In this paper we propose a new approach to the construction of monotonic difference schemes of second-order approximation, which is based on the investigation of differential approximations of schemes. We give monotonic nonlinear schemes of second-order approximation for linear and nonlinear transport equations. A generalization for the case of moving nonuniform grids and the system of shallow water equations is made.

A 3D numerical model of thermal convection in the upper Earth mantle is constructed, which is based on ‘vector potential-vorticity' variables and the subincremental method. Its thorough testing is carried out. Computational results that demonstrate the substantially 3D structure of convective fluxes in the Earth mantle are given.