Two-Fluid 2.5D MHD-Code for Simulations in the Solar Atmosphere

We investigate magnetic reconnection due to the evolution of magnetic flux tubes in the solar chromosphere. We developed a new numerical two-fluid magnetohydrodynamic (MHD) code which will perform a 2.5D simulation of the dynamics from the upper convection zone up to the transition region. Our code is based on the Total Variation Diminishing Lax-Friedrichs scheme and makes use of an alternating-direction implicit method, in order to accommodate the two spatial dimensions. Since we apply a two-fluid model for our simulations, the effects of ion-neutral collisions, ionization/recombination, thermal/resistive diffusivity and collisional/resistive heating are included in the code. As initial conditions for the code we use analytically constructed vertically open magnetic flux tubes within a realistic stratified atmosphere. Initial MHD tests have already shown good agreement with known results of numerical MHD test problems like e.g. the Orszag-Tang vortex test

Solar Science with the Atacama Large Millimeter/Submillimeter Array — A New View of Our Sun

The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution. These capabilities can address a broad range of fundamental scientific questions in solar physics. The radiation observed by ALMA originates mostly from the chromosphere—a complex and dynamic region between the photosphere and corona, which plays a crucial role in the transport of energy and matter and, ultimately, the heating of the outer layers of the solar atmosphere. Based on first solar test observations, strategies for regular solar campaigns are currently being developed. State-of-the-art numerical simulations of the solar atmosphere and modeling of instrumental effects can help constrain and optimize future observing modes for ALMA. Here we present a short technical description of ALMA and an overview of past efforts and future possibilities for solar observations at submillimeter and millimeter wavelengths. In addition, selected numerical simulations and observations at other wavelengths demonstrate ALMA’s scientific potential for studying the Sun for a large range of science cases

Theory and interpretation of solar decimetric radio bursts.

Observed radio data could hardly be used to diagnostics of solar flare plasmas without solid theoretical background that allows their correct interpretation. The main goal of the thesis was just to contribute to this background knowledge. This problem appears to have two aspects: identification of physical processes whose radio manifestation was recorded and determination of relations between plasma parameters in the radio source and values of observed radio flux. Both aspects were concerned within the thesis.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

FEM analysis of main parts of a manipulator for mountig a compressor to a car equipped with a pneumatic suspension system

The article deals with a FEM analysis of main parts of an engineering design of a pneumatically controlled manipulator, which will serve for mounting a compressor to a PO536 car chassis. This car chassis belongs to SUV cars and it is equipped with a pneumatic suspension system. It is the chassis of a Porsche Cayenne car produced in the Slovak Republic. The designed manipulator will be located on the assembly line of this vehicle. Except of FEM analyses of designed important parts of the manipulator, which are necessary for verification of safety of the design in order to obtain distribution of stresses and deformations in a structure, the it contains also the design of a pneumatic circuit of the manipulator together with pneumatic logic and it individual components. Based on three-dimensional model, there will be possible to generate drawings of the manipulator for manufacturing of the device and its application to the real operation

Engineering design of a manipulator for mounting an air suspension compressor to a car chassis

This article is aimed at the engineering design of a manipulator, which is pneumatically controlled. It will serve for mounting the compressor of an air suspension system to the chassis of a sport utility vehicle (SUV) produced in the Slovak Republic. The manipulator will be used on an assembly line, on which SUVs are assembled. The designed device belongs to a group of dedicated devices, which are not produced within a serial production, however, it is the only functional prototype. Together with the manipulator structure, a pneumatic part of the assembly line including individual components, schemes and the pneumatic system will be proposed. Within the project process, all necessary customer demands, technical and safety standards have to be met. Moreover, ergonomic requirements for handling the device and other acts on the workplace have to be considered

DESIGN OF A METRO DOOR SYSTEM AND DETERMINATION OF MAIN LOADS

This article discussed the determination of a metro vehicle’s door forces acting on its coarse structure. With previous articles addressing this issue, a definition of a specific reference vehicle was provided together with the collection of the normative requirements for metro vehicles. These form a basis for addressing the issue. The main objective hereof was to design a technical solution of a door system for the reference vehicle and create a parametric model of the door's forces acting on the vehicle’s rough structure. This model would serve to approximate and operatively quantify these force effects of the door to the vehicle’s structure by modifying the various input parameters. Therefore, it was necessary to create a mathematical model of the equilibrium conditions of the proposed door system and to quantify them using a developed software. Subsequently, these results served as inputs for the FEM analysis of the load-bearing components between the door and the vehicle’s structure