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ACOUSTIC SIMULATION - RUN UP ANALYSIS OF NEW AUDI V8 OTTO ENGINE

Fischer, Peter
Holzer, Siegfried
Tanzer, David
Tapp, Christoph
DTECH STEYR, Austria; AUDI AG, Germany

Abstract

A method for industrial application of an engine run-up simulation is presented. The method is demonstrated for the
new Audi V8 4,2 liter Otto engine. The run-up simulation is performed for the whole operating range of engine speeds.
The analysis procedure bases on a modal frequency response solution for small steps of increasing engine speeds. To
facilitate the update of the excitation data, the excitation is formulated in terms of power spectra and cross spectra.
Local damping is introduced for the most important damping mechanisms of the engine, i.e. for joints, different
materials and surfaces with fluid contact. This leads to a high quality of the simulated response and an information
density which can be directly compared to Campbell diagrams of measured run-ups.

ACOUSTIC SIMULATION - RUN UP ANALYSIS OF NEW AUDI V8 OTTO ENGINE (PDF, 2.2 MB)

Abstract Syntax Trees in XML

David Tanzer
Johannes Kepler Universität Linz, Institut für Systemsoftware

Abstract

In the last few years, XML has become the method of choice for all kinds of structured data. There
are many benefits of using XML to define a data representation. This can be compared to the
introduction of standard containers in transport and logistics: They made easy interaction of all
involved parties possible. To have a common format for data representation like XML increases the
interoperability of computer programs in the same way.

There are many standard ways of dealing with XML, for example one can find open source XML
parsers for almost all programming languages. In many modern programming languages XML
support is even built-in. With XSL Transformations there is a standard way of transforming XML to
other formats, and Document Type Definitions of XML Schema Definitions allow it to define the
structure of an XML document.

In this thesis XML is used to represent the “Abstract Syntax Tree” of a compiler. The abstract
syntax tree is an internal representation which is generated by the parser of a compiler when it
analyzes a source file. This abstract syntax tree is highly structured so it can be easily represented
by an XML document which has a tree structure too.

Abstract Syntax Trees in XML (PDF, 3.0 MB)