VIBRATION OF CAVITATING ELASTIC WING IN A PERIODICALLY PERTURBED FLOW: EXCITATION OF SUBHARMONICS

✍ Scribed by E. AMROMIN; S. KOVINSKAYA

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 223 KB
• Volume: 14
• Category: Article
• ISSN: 0889-9746
• DOI: 10.1006/jfls.2000.0291

✦ Synopsis

The vibration of an elastic wing with an attached cavity in periodically perturbed #ows is analyzed. Because the cavity thickness and length ¸also are perturbed, an excitation with a "xed frequency leads to a parametric vibration of the wing, and the amplitudes and spectra of its vibration have nonlinear dependencies on the amplitude of the perturbation. Numerical analysis was carried out for a two-dimensional #ow of ideal #uid. Wing vibration was described by means of the beam equation. As a result, two frequency bands of a signi"cant vibration increase were found. A high-frequency band is associated mainly with an elastic resonance of the wing, and a cavity can add a certain damping. A low-frequency band is associated with cavity-volume oscillations. The governing parameter for the low-frequency vibration is the cavity length-based Strouhal number St ! " ¸/;, where ; is the free-stream speed. The most signi"cant vibration in the low-frequency band corresponds to approximately constant values of Sh ! and has the most extensive subharmonics. 2000 Academic Press VIBRATION OF CAVITATING ELASTIC WING