Unidirectional Periodic Flow About Circular Cylinders.
Abstract
The instantaneous force acting on a circular cylinder immersed in a unidirectional periodic flow characterized by U = V + (V sub A) sin 2 (PL) ft was investigated. The total force was divided into three components consisting of a steady-state drag; an oscillating drag which is a function of the frequency parameter lambda = fd/V ; and an inertial force which is also a function of the frequency parameter. The three resistance coefficients associated with the force components, (C sub D), (C sub D)(lambda), and (C sub M)(lambda) were calculated. It was found that the resistance coefficients are not materially affected by the free-stream oscillations whenever the frequency of the vortex shedding. However, when lambda- approaches the Strouhal frequency of vortex shedding, the inertia coefficient (C sub M) is significantly reduced, and likewise when lambda approaches the value of twice the Strouhal number, (C sub D)(lambda) is markedly reduced. In regions below this range, the inertial force becomes negligible. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1973
- Accession Number
- AD0764487
Entities
People
- Richard Doyle Greenamyer
Organizations
- Naval Postgraduate School