Ahlefeldt, Thomas and Koop, Lars (2009) Microphone-Array Measurements in a Cryogenic Wind Tunnel. 15th AIAA/CEAS Aeroacoustic Conference, 2009-05-11 - 2009-05-13, Miami, FL (USA).
Full text not available from this repository.
Based on previous studies with microphones and electronic equipment in a cryogenic environment, a test array for cryogenic application has been developed. Electret microphones, electronic equipment and fairing material have been successfully tested by the authors under cryogenic conditions and have demonstrated long-term stability. Subsequently, in this paper, acoustic array measurements performed in a cryogenic wind tunnel for various temperatures in the range 100 K to 300 K using a single rod configuration are described. The Mach number was in range 0.1 to 0.3 and the Reynolds number (based on the cylinder diameter of 2.5 mm) was in the range 5·103 to 8·104. The experiments demonstrated the technical feasibility of performing aeroacoustic array measurements at these low temperatures. A systematic study of Reynolds and Mach number effects on the radiated noise of a single rod configuration has been conducted. The results showed reasonably good agreement between theory and measured sound radiation. A Reynolds number dependency of the measured and predicted sound power can be shown. At a later stage, a large array for cryogenic application, which was modeled on the test array used here, has been constructed and preliminary results of measurements on a Dornier DO-728 half-model are also presented here.
|Document Type:||Conference or Workshop Item (Speech, Paper)|
|Title:||Microphone-Array Measurements in a Cryogenic Wind Tunnel|
|In ISI Web of Science:||No|
|Page Range:||pp. 1-16|
|Series Name:||CD Conference Proceedings|
|Keywords:||microphone-array, closed test-section, aeroacoustic noise sources, cryogenic wind tunnel|
|Event Title:||15th AIAA/CEAS Aeroacoustic Conference|
|Event Location:||Miami, FL (USA)|
|Event Type:||international Conference|
|Event Dates:||2009-05-11 - 2009-05-13|
|HGF - Research field:||Aeronautics, Space and Transport (old)|
|HGF - Program:||Aeronautics|
|HGF - Program Themes:||Aircraft Research|
|DLR - Research area:||Aeronautics|
|DLR - Program:||L AR - Aircraft Research|
|DLR - Research theme (Project):||L - Flight Physics|
|Institutes and Institutions:||Institute of Aerodynamics and Flow Technology > Experimental Methods|
|Deposited By:||Ilka Micknaus|
|Deposited On:||04 Aug 2009 15:57|
|Last Modified:||13 Oct 2009 10:14|
Repository Staff Only: item control page