Accession Number : ADA324614

Title :   Use of a Correlation Coefficient for Conditional Averaging.

Descriptive Note : Final rept. Feb-Mar 97,

Corporate Author : ARMY RESEARCH LAB ADELPHI MD

Personal Author(s) : Loucks, Richard B.

PDF Url : ADA324614

Report Date : APR 1997

Pagination or Media Count : 18

Abstract : A method of collecting ensembles for conditional averaging is presented that uses data collected from a plane mixing layer. The correlation coefficient of a sine function and a reference signal were used to determine the adequacy of blocks of the reference signal and the phase alignment for the data. Selection of the sine function period and a correlation coefficient threshold are discussed. Also examined are the effects of the period and threshold level on the number of ensembles captured for inclusion for conditional averaging. Both the selection of threshold correlation coefficient and the choice of data set length determine bandpass filtering; this study examined the effect of these choices on the ability to discriminate reference velocity ensembles for conditional averaging.

Descriptors :   *TURBULENT FLOW, *CORRELATION TECHNIQUES, VELOCITY, DATA BASES, THRESHOLD EFFECTS, ALIGNMENT, COEFFICIENTS, SIGNALS, FAST FOURIER TRANSFORMS, BANDPASS FILTERS, DISCRIMINATE ANALYSIS, SINE WAVES.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE