A Correction Method for Turbulence Measurements with a 3D Acoustic Doppler Velocity Profiler

摘要

A method is proposed to reduce the noise contribution to mean turbulence parameters obtained by 3D acoustic Doppler velocity profiler measurements. It is based on a noise spectrum reconstruction from cross-spectra Evaluations of two independent and simultaneous measurements of the same vertical velocity component over The whole water depth. The noise spectra and the noise variances are calculated and removed for the three Fluctuating velocity components measured in turbulent, open-channel flow. The corrected turbulence spectra Show a -5/3 slope over the whole inertial subrange delimited by the frequency band of the device, while the Uncorrected turbulence spectra have flat high-frequency regions typical for noise effects.