AEROACOUSTICAL STUDY OF THE TGV PANTOGRAPH RECESS

✍ Scribed by C. NOGER; J.C. PATRAT; J. PEUBE; J.L. PEUBE

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 419 KB
• Volume: 231
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1999.2545

✦ Synopsis

The general focus of this aerodynamic noise research, induced by turbulent incompressible #ow, is to improve our knowledge of acoustic production mechanisms in the TGV pantograph recess in order to be able to reduce the radiated noise. This work is performed under contract with SNCF as a part of the German}French Cooperation DE;FRAKO K2, and is supported by French Ministries for Transport and Research. Previous studies on TGV noise source locations (DE;FRAKO K) have identi"ed the pantograph recess as one of the important aerodynamic noise sources, for speeds higher than 300 km/h, due to #ow separation. The pantograph recess is a very complex rectangular cavity, located both on the power car and the "rst coach roofs of the TGV, and has not been studied before due to the complex shapes. Its aeroacoustic features are investigated experimentally in a low-subsonic wind tunnel, on a realistic 1/7th scale mock-up both with and without pantographs. Flow velocities, estimated with hot-wire anemometry, and parietal visualizations show the #ow to reattach on the recess bottom wall and to separate again at the downstream face. Wall pressure #uctuations and &&acoustic'' measurements using and in microphones respectively are also measured to qualify the #ow: no aerodynamic or acoustic oscillations are observed. The study indicates that the pantograph recess has a di!erent behaviour compared to the usual cavity grazing #ows.