Bm. Abraham et Wl. Keith, WAVE-NUMBER SPECTRA OF HIGH MAGNITUDE WALL-PRESSURE EVENTS IN A NUMERICALLY SIMULATED TURBULENT BOUNDARY-LAYER, Journal of fluids engineering, 119(2), 1997, pp. 281-288
A method for conditionally sampling the spatial field of the wall pres
sure beneath a turbulent boundary layer in order to search for high ma
gnitude events and calculate the corresponding wavenumber spectrum is
presented. The high magnitude events are found using a simple peak det
ection algorithm at a fixed instant in time and the wavenumber spectra
are calculated using discrete Fourier transforms. The frequency of oc
currence Soi high magnitude positive events is found to be approximate
ly the same as for high magnitude negative events. The contribution of
the high magnitude events to the rms wall pressure for various trigge
r levels is calculated and compared with results from similar experime
ntal studies performed in the time domain. The high magnitude events a
re shown to occur infrequently and to contribute significantly to the
rms wall pressure. Wavenumber spectra from the high magnitude positive
and negative events are calculated and compared with the unconditiona
lly sampled spectra. The high magnitude events contain energy focused
around a particular streamwise wavenumber and have high broadband spec
tral levels.