TY - JOUR

T1 - Experimental validation of unsteady pressure-sensitive paint for acoustic applications

AU - Gößling, Jan

AU - Ahlefeldt, Thomas

AU - Hilfer, Michael

N1 - Funding Information: The authors would like to thank and acknowledge Akif Mumcu, M.Sc. Dipl.-Ing. Michael Henke and Prof. Jörg Seume from Leibniz University Hannover, Institute of Turbomachinery and Fluid Dynamics for their valuable support. Furthermore we would like to thank Dr. Yorita Daisuke, Dr. Christian Klein, Dr. Daniel Ernst, Dr. Carsten Spehr, Carsten Fuchs and Tobias Kleindienst from German Aerospace Center, Institute of Aerodynamics and Flow Technology, Göttingen for their important support. Also many thanks to Miku Kasai and Prof. Keisuke Asai from Tohoku University for allowing and performing the iPSP calibrations.

PY - 2020/4/1

Y1 - 2020/4/1

N2 - Fast response Pressure-Sensitive Paint (iPSP) developed at the German Aerospace Center (DLR) in Göttingen is evaluated for measurements of acoustic pressure distributions. A test facility is constructed, which allows to measure these acoustic pressure distributions with iPSP. The aim of this evaluation is to detect pressure amplitudes below 100 Pa with sinusoidal and white noise acoustic excitation between 1 and 4 kHz. The following data analysis methods are applied to increase the signal-to-noise ratio (SNR): phase averaging, proper orthogonal decomposition (POD), dynamic mode decomposition (DMD), and fast Fourier transform (FFT). DMD is identified to be very powerful in extracting acoustic pressure fluctuations and eliminating image noise, but FFT achieves comparable results in this application. The used measurement setup combined with the DMD or FFT are capable of detecting pressure levels below 11 Pa or 114 dB sound pressure level (SPL) in cases with white noise excitation with detected mode frequencies up to 4615 Hz. The minimal detectable pressure limit during this investigation is 5 Pa or 108 dB (SPL) at 1318 Hz and sinusoidal acoustic excitation. The results from iPSP are compared to conventional measurement technique, flush with the surface mounted microphones, with good agreement.

AB - Fast response Pressure-Sensitive Paint (iPSP) developed at the German Aerospace Center (DLR) in Göttingen is evaluated for measurements of acoustic pressure distributions. A test facility is constructed, which allows to measure these acoustic pressure distributions with iPSP. The aim of this evaluation is to detect pressure amplitudes below 100 Pa with sinusoidal and white noise acoustic excitation between 1 and 4 kHz. The following data analysis methods are applied to increase the signal-to-noise ratio (SNR): phase averaging, proper orthogonal decomposition (POD), dynamic mode decomposition (DMD), and fast Fourier transform (FFT). DMD is identified to be very powerful in extracting acoustic pressure fluctuations and eliminating image noise, but FFT achieves comparable results in this application. The used measurement setup combined with the DMD or FFT are capable of detecting pressure levels below 11 Pa or 114 dB sound pressure level (SPL) in cases with white noise excitation with detected mode frequencies up to 4615 Hz. The minimal detectable pressure limit during this investigation is 5 Pa or 108 dB (SPL) at 1318 Hz and sinusoidal acoustic excitation. The results from iPSP are compared to conventional measurement technique, flush with the surface mounted microphones, with good agreement.

KW - Acoustic

KW - Data analysis

KW - DMD

KW - Dynamic mode decomposition

KW - FFT

KW - iPSP

KW - POD

KW - Pressure-Sensitive Paint

KW - Proper orthogonal decomposition

KW - SPL

KW - Surface measurement

UR - http://www.scopus.com/inward/record.url?scp=85075757926&partnerID=8YFLogxK

U2 - 10.1016/j.expthermflusci.2019.109915

DO - 10.1016/j.expthermflusci.2019.109915

M3 - Article

AN - SCOPUS:85075757926

VL - 112

JO - Experimental Thermal and Fluid Science

JF - Experimental Thermal and Fluid Science

SN - 0894-1777

M1 - 109915

ER -