Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 21 for “"Numerisches Verfahren"”.
-
Parallele Implementierung und Analyse eines expliziten Adams-Verfahrens
Das Adams-Bashforth-Verfahren ist ein numerisches Verfahren zur Lösung von gewöhnlichen Differentialgleichungen. In dieser Arbeit werden mehrere Implementierungsvarianten des Adams- Bashforth-Verfahrens vorgestellt, verglichen und analysiert. Zunächst arbeiten die Implementierungen sequentiell. …
-
Hochauflösende Verfahren zur numerischen Berechnung von strahlungsgetriebenen Scheibenwinden
… Erhaltungsgleichungen wird ein neues numerisches Verfahren für krummlinige Gitter entwickelt. Umfangreiche Tests belegen, dass die mit dieser Methode gewonnenen Resultate eine im Vergleich mit anderen Verfahren mindestens ebenso gute Approximation für die tatsächlichen Lösungen …
-
Multidimensional systems of hyperbolic conservation laws, numerical schemes, and characteristic theory : connections, differences, and numerical comparison
Many physical problems, for example the behaviour of a compressible fluid, can be modelled as systems of hyperbolic conservation laws, d/dt U + div.F(U) = 0, if certain effects (for instance viscosity) are neglected. One of the first computational schemes for systems of conservation laws was …
-
Beitrag zur numerischen Analyse der Schädigungsmechanismen von Naturzugkühltürmen
In the present work the progressive damage process of natural draught cooling towers is analysed numerically. A non-linear composite material model for the reinforced concrete is formulated. Regarding the durability a special attention is paid to the cracking process and the determination of the …
-
Kinetic mechanisms for hydrocarbon ignition
The origins of detailed and reduced kinetic models for the ignition and oxidation of alkanes and aromatic hydrocarbons have been traced in this study and their development and application in the prediction of some aspects of hydrocarbon fuels have been explored. The scope and limitations for the …
-
Optimierung der Kernherstellung durch numerische Simulation
The core shooting process is based on the sudden expansion of a limited compressed air volume, which shoots the molding material into the core box with high velocity. Apart from the mould filling the purpose is to release an adequate compression of the molding material. During the entire time it is …
-
Numerische Untersuchung von N 2 -O 2 -Plasma-Freistrahlen als plasmatechnologische Methode zur NO x -Reduktion in synthetischen Abgasen
The attempt to use microwave induced N2-O2 plasmas to reduce NOx emissions of direct injecting gasoline and Diesel engines reaching the limits of the EURO 4 exhaust gas standards is of special interest. This work makes the attempt to explore the fundamental plasmachemical reaction paths of NOx …
-
Wärmebelastung der Brennkammer eines Staustrahltriebwerks mit Überschallverbrennung
The aim of the dissertation project is the numerical simulation of the flow in a scramjet combustion chamber with diabatic walls. In order to analyze the aerothermal load on the structure and to determine the energy loss of the flow, an integrated fluid-thermal-structural analysis is performed. Of …
-
A semigroup approach to the numerical solution of parabolic differential equations
This work is concerned with the numerical solution of linear parabolic differential equations. We exploit the framework of analytic semigroups to understand the properties of the solution as well as to develop numerical algorithms. In the first chapter, we focus on the homogeneous problem. A short …
-
Beugungssimulation ohne Rechenzeitexplosion: Die Methode der quantisierten Pyramidenstrahlen : ein neues Berechnungsverfahren für Raumakustik und Lärmimmissionsprognose ; Vergleiche, Ansätze, Lösungen
In room acoustics and noise immission prognosis, basically three algorithms for the computation of sound fields are in use. These are, in the order of reflection where they are efficient: the mirror image source method ray tracing methods (ray or beam tracing), among these tracing and recursive …
-
Thermochemische und kinetische Modellierung zur Legierungsauswahl mehrphasiger Systeme für das Thixoforming und zur Optimierung ihrer Formgebungsprozesse
In the present work the thermochemical calculations for the selection of alloys and for the process optimisation of the semi-solid processing (SSP) were carried out. The available thermodynamic data for aluminium systems were extended. Two quaternary systems Al-Fe-Mn-Si and Al-Cu-Li-Mg were …
-
Einfluss des Treibergases auf die Strömung in Stoßwellenkanälen
One of the main aspects of space transportation is the aerodynamic of space vehicles. For the investigation of flow problematic and the interrelated transport phenomenas in hypersonic flows, the development of suitable tools is required. Here, development and verification of such tools is …
-
Physikalische und numerische Simulation von Stauraumkanälen mit unten liegender Entlastung
Deterring the waste in the sewerage system and preventing water pollution during storm water events is the task of Combined Sewer Detention Tanks (CSDT). CSDTs are components of combined sewerage systems, the most-used sewerage-system in Germany. The aim is to realise an ecological en economical …
-
Ein modulares Verfahren für die numerische aeroelastische Analyse von Luftfahrzeugen
In order to assure economic efficiency and operational safety of new aircrafts, it is necessary to accurately consider the interaction of the elastic aircraft structure and the airflow in early stages of design. For a reliable prediction of effects arising from the interaction of the fluid and the …
Page 1 of 2