Trailing-Edge Noise Data Quality Assessment for CAA Validation

Abstract

The paper provides a detailed reexamination of previously published trailing-edge (TE) noise experimental data as acquired in DLR's low-noise open-jet Acoustic Wind Tunnel Braunschweig (AWB). The objective is to set up a parametric reference data base to be later used for CAA validation purposes. A modular plate airfoil with variable chord length was used to investigate Reynolds number effects on both near field quantities and farfield sound. The original data base, including corrected farfield TE noise spectra as well as turbulent boundary-layer (TBL) characteristics, has been extended by unsteady surface pressure measurements in the TE region. Limitations and weaknesses of the applied measurement techniques are pinpointed by comparisons with independent data sets using alternative measurement approaches. Comparisons include also available semi-empirical prediction models for surface pressure spectra as well as for farfield TE sound emission. First RANS-based CAA prediction results using stochastic source models show essential agreement with the measurement data.