Oscillating Flow About Circular Cylinders at Low Keulegan-Carpenter Numbers.
Abstract
The in-line force and the resulting drag and inertia coefficients for smooth and rough circular cylinders immersed in a sinusoidally oscillating flow at low Keulegan-Carpenter numbers (K) have been determine experimentally and compared with those obtained theoretically by Stokes and Wang. In addition, flow visualization experiments were carried out with oscillating cylinders in a water table and the stability of the flow was investigated. The results have shown that for very low values of K, the flow about the cylinder is laminar, attached, and stable and the drag coefficient is nearly identical to that predicted theoretically. At a critical K, the flow becomes unstable to Taylor-Gortler vortices and the drag coefficient jumps to a higher value. Subsequently, the flow separates, becomes turbulent and results in a minimum drag coefficient. The subsequent increases in drag are attributed to vortex shedding. The inertia coefficient agrees with that obtained theoretically in the range where the flow is laminar.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1985
- Accession Number
- ADA161186
Entities
People
- Nathan Q. S. Yuen
Organizations
- Naval Postgraduate School