INTERACTION BETWEEN AIR FLOW AND AIR -BORNE SOUND IN A DUCT.
Abstract
The interaction of a surface bending wave with the flow boundary layer is of practical interest. Several types of surfaces conducting bending waves suitable for boundary layer interaction are tested. For the investigation of the influence of the flow velocity profile in a ducton the sound attenuation the sound pressure profiles in a wide duct with flow were measured. The acoustic impedance of an absorber with flow along its surface was measured. The sound radiation from an orifice with flow discharge depends on the flow velocity. The reflection coefficient of the orifice increases with flow velocity. It depends strongly on the turbulence level of the jet behind the orifice. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1963
- Accession Number
- AD0631354
Entities
People
- F. P. Mechel
- P. A. Mertens
- W. M. Schilz
Organizations
- University of Göttingen