Wavelet analysis of in-cylinder LDV measurements

 MAGNUS WIKTORSSON*  , BENGT LINDOFF*    BENGT JOHANSSON**  AND FREDRIK SÖDERBERG**

 *  Centre for Mathematical Sciences Lund University

 ** Division of Combustion Engine Department of Heat and Power Lund University
    

Abstract

The object of this paper is to present a new way analyzing in-cylinder
mesurements. The technique is called Discrete Wavelet Transform (DWT)
and it is similar to Fast Fourier Transform (FFT) with one important
difference: it is possible to obtain both time localized and frequency
resolved information. This paper demonstrates the use of DWT
calculations on in-cylinder LDV flow measurements for different
combustion geometries in a natural gas converted truck engine. It will
furthermore provide some information about how DWT can used with
in-cylinder mesurements in the future.