Transverse Oscillations of Smooth and Rough Cylinders in Harmonic Flow.
Abstract
The dynamic response of elastically-mounted cylinders in a sinusoidally oscillating two-dimensional flow has been investigated both theoretically and experimentally. The experiments were carried out in a large U-shaped water tunnel, with smooth and sand-roughened circular cylinders. The results have been expressed in terms of lift coefficients, relative amplitudes of oscillation, Keulegan-Carpenter number, Reynolds number, Strouhal number, and a mass parameter. A theoretical analysis has been carried out by assuming the transverse force varies harmonically. Furthermore, the instantaneous values of the displacement have been predicted through the use of the Duhamel's integral. The results have shown that elastically-mounted cylinders undergo synchronous oscillations at a reduced velocity of 5.7 when the vortex shedding frequency coincides with the natural frequency of the cylinder. Away from the region of synchronization the cylinder is subjected to forced response by vortices shedding at a frequency smaller or larger than the natural frequency of the cylinder. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1979
- Accession Number
- ADA078271
Entities
People
- Suleyman Ozkaynak
Organizations
- Naval Postgraduate School