Application of Discrete Wavelet Transform in a Combustion Chamber to Turbulence Measurement with LDV (Removing Noise in Measurement Data Using Wavelet Shrinkage)
Zhong Zhang, Eiji Tomita · TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B · 2004
In this study, the influence of the measurement noise in LDV measurements were considered, and how to remove the noise using Complex Discrete Wavelet Transform (CDWT) was proposed. Then turbulent velocity in the combustion chamber measured with an LDV was analyzed. The major results can be summarized as follows : 1) The influence of the noise in the turbulent velocity becomes large as frequency increases. Therefore, a setup of cutoft frequency is difficult when removing the noise with a lowpass filter. 2) In this case, it is effective to remove the noise using the CDWT because of improvement of translation invariance.