Combination of numerical models of deformations and repeated geodetic measurement results provide reliable information on the state of the rock mass in a mining area and support planning and control of the mining operation. The paper describes the concept of integrated monitoring and analysis of rock mass deformation in the Kvannevann iron ore mine (Norway) using sub-level caving (SLC) method. Geodetic control network developed for periodic measurements of surface subsidence and a source of geometrical data for numerical modelling of deformations using finite element method (FEM) has been characterised. Focus is given to the results of initial numeric al analyses with FEM of rock mass deformations due to SLC mining. The results of the modelling provided information on possible extent of deformation zones on the mining ground surface once mining with new method commences., Jan Blachowski and Steinar Ellefmo., and Obsahuje bibliografické odkazy
The paper deals with design optimization of a capacitive micromachined switch consisting of a thin membrane suspended over a central conductor. The aim is to achieve as small necessary electrostatic pull-in force as possibble while ensuring fast switching. Optimum parameters are searched using fast linear and nonlinear beam models verified by the finite element method. and Obsahuje seznam literatury
The aim of the paper is to propose a definition of numerical range of an operator on reflexive Banach spaces. Under this definition the numerical range will possess the basic properties of a canonical numerical range. We will determine necessary and sufficient conditions under which the numerical range of a composition operator on a weighted Hardy space is closed. We will also give some necessary conditions to show that when the closure of the numerical range of a composition operator on a small weighted Hardy space has zero.
We study numerical semigroups $S$ with the property that if $m$ is the multiplicity of $S$ and $w(i)$ is the least element of $S$ congruent with $i$ modulo $m$, then $0<w(1)<\dots <w(m-1)$. The set of numerical semigroups with this property and fixed multiplicity is bijective with an affine semigroup and consequently it can be described by a finite set of parameters. Invariants like the gender, type, embedding dimension and Frobenius number are computed for several families of this kind of numerical semigroups.
The paper deals with the numerical solution of 3D transonic flow through axial turbine cascades. Finite volume methods based on TVD MacCormack cell-centered and Ni’s cell-vertex schemes are discussed. A comparison of numerical results for 3D stator and rotor cascades is presented.
In this paper the numerical approximation of a two dimensional aeroelastic problem is addressed, where nonlinear effects are considered. For the flow model we use the Navier-Stokes equations, spatially discretized by the FE method and stabilized with a modification of the Galerkin Least Squares (GLS) method. The motion of the computational domain is treated with the aid of the Arbitraty Lagrangian Eulerian (ALE) method. The structure model is considered as a solid body with two degrees of freedom (bending and torsion). The motion is described with the aid of a system of nonlinear differential equations and coupled with the flow model by the strongly coupled algorithm. and Obsahuje seznam literatury
The contribution presents a mathematical and numerical investigation of the Atmospheric Boundary Layer (ABL) flow over the real configuration given by a brown coal mine and coal depot in North Bohemia. The influence of various types of protective
obstacles (as forest blocks, tree-line, walls) on the reduction of dustiness has been studied.
The mathematical models are based on the system of Reynolds Averaged Navier-Stokes (RANS) equations for a viscous incompressible flow. The full system of RANS equations in conservative form was solved using finite-volume explicit scheme and artificial compressibility method. A simple algebraic turbulent model was used for the closure of the basic system of equations. Additional transport equation for passive pollutant has been considered in order to study the pollution dispersion over the
complex 3D topography. The forest stand is simulated using the additional source term in the momentum equations which depends on the local velocity magnitude, the characteristic area of the obstacle and on the drag coefficient. and Obsahuje seznam literatury
Flow of particles suspended in a fluid can be found in numerous industrial processes utilizing sedimentation, fluidization and lubricated transport such as food processing, catalytic processing, slurries, coating, paper manufacturing, particle injection molding and filter operation. The ability to understand rheology effects of particulate flows is elementary for the design, operation and efficiency of the underlying processes. Despite the fact that particle technology is widely used, it is still an enormous experimental challenge to determine the correct parameters for the process employed. In this paper we present \mbox{2-dimensional} numerical results for the behavior of a particle based suspension and compare it with analytically results obtained for the Stokes-flow around a single particle.
The article deals with the numerical simulation of unstable, incompressible flows with stratifications. The mathematical model is based on the Boussinesq approximation of the Navier-Stokes equations. The flow field in the towing tank with a moving cylinder is modeled for wide range of Richardson numbers. The obstacle is modeled via appropriate source terms. The resulting set of PDE is then solved by the fifth oorder WENO scheme, or by a second order finite volume AUSM MUSCL scheme. Both schemes are combined with the artificial compressibility method in dual time. and Obsahuje seznam literatury