1. The results produced by the beamforming software for different inputs is shown in Figs. 10a-11c. Theprocessed resultsfromtheDNW-LLFtestisshowninFig. 10a. Theresultswithasimulatedcross-spectralmatrix,i.e. Eq. 7,are shown inFig. 10b. When thecoherence lossis disabledin thesimulation theresult becomesFig. 10c. These results (a) Raw wind tunnel results @ 10 kHz (b) Modelled data with coherence loss (c) Modelled datawithout coherenceloss
2. Theresultsshowthatcoherencelossduetothickturbulentboundarylayers,asmodelledcurrently,leadstoonly slightlyunderestimatedbeamformedSPLmapsbelow30kHz. ThedecreaseofSPLismainlyfoundathigherfrequencies, where the predicted loss is approximately 4-5 dB. Coherence loss was found to induce blurring of the beamforming maps from20 kHzon, evenfora singlepoint source. Coherenceloss modellingin aeroacousticapplication remains however difficult to predict using methods that are borrowed from the atmospheric sciences. From measurements done
3. Predicting Turbulent Decorrelation in Acoustic Phased Arrays