Accession Number : AD0764487

Title :   Unidirectional Periodic Flow About Circular Cylinders.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Greenamyer,Richard Doyle

Report Date : JUN 1973

Pagination or Media Count : 61

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)

Descriptors :   (*FLUID FLOW, CYLINDRICAL BODIES), LAMINAR FLOW, HYDRODYNAMICS, TURBULENCE, PARTIAL DIFFERENTIAL EQUATIONS, NUMERICAL ANALYSIS, THESES

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE