Developing a Method for Shortening the Model-Based Application Process in Large Bore Engine Development

Dissertation, 2017

from Dr.-Ing. Christian Friedrich

Abstract

The present thesis describes the development of the EVoMoT-method, a methodology for transferring results from single cylinder to full scale engines in terms of model-based calibration in large bore engine development.

The motivation for the methodology’s development is given by high test bench costs and long test bench times for calibration purposes of modern large bore engines at the test benches. Although large bore engines have lower specific fuel consumptions compared to commercial vehicle or automotive engines, the absolute fuel oil consumptions are significantly higher. Furthermore, the stabilization times to reach steady state behaviour are much longer in terms of large bore engines. In spite of the introduction of model-based calibration techniques for large bore engine development the resulting number of measurements still requires an extensive scope. Therefore, the developed methodology pursues the objective to further reduce the amount of measurements of the full scale engine by transferring the results of significantly more cost-efficient single cylinder engine measurement results to the full scale engine.

Using an extensive amount of measurement results of the single cylinder engine and significantly reduced measurements of the full scale engine transfer functions between single cylinder and full scale engine for chosen steady state engine outputs are developed, enabling the generation of calculated data points of the full scale engine. These measurement data are used to build full scale engine regression models to perform optimizations and create engine maps of setpoints for the engine control unit. Modeling techniques as radial basis function networks and Gaussian process models have been utilized to model the behaviour of large bore engines for the first time.

The developed methodology is presented with a simple demonstration example and validated by application to a real large bore engine. Single cylinder measurement results of chosen steady state engine outputs as specific fuel oil consumption, specific nitrogenoxid emissions, soot emissions, maximum cylinder pressure and exhaust temperature have been transferred successfully by generated transfer functions to the full scale engine. Valid full scale engine models of these engine outputs have been built and used to create engine maps for the engine control unit.

Extent: 169 pages

ISBN: 978-3-943813-23-4

Price: 33 € ( 2 € for dispatch)

Ordering: verlag(at)lvk.mw.tum.de