Accession Number : AD0656689

Title :   THE RESPONSE OF A CYLINDRICAL STRUCTURE TO A TURBULENT FLOW FIELD AT SUBCRITICAL REYNOLDS NUMBER,

Corporate Author : TORONTO UNIV (ONTARIO) INST FOR AEROSPACE STUDIES

Personal Author(s) : Campbell,A. C. ; Etkin,B.

Report Date : JUL 1967

Pagination or Media Count : 60

Abstract : A wind tunnel study was made of the bending moment response of a cylindrical structure exposed to a turbulent wind. A theory, developed by Etkin, of the response of a slender structure in the stream direction to a turbulent wind was compared with the experimental results. The structure used for the study was an approximate aeroelastic model of an existing radio antennas. A turbulence field was generated in the wind tunnel by a square mesh grid. With a ratio of longitudinal turbulence scale to model diameter of L/D = 21 and an intensity of 20% the model in this turbulence field was then representative of a full scale structure in atmospheric turbulence. Bending moment spectra in the drag and lift directions were obtained for various turbulence conditions. It was found that close agreement was obtained between theory and experimental results in the turbulence field. This indicates that the drag coefficient for this cylinder is very similar under turbulent and steady wind conditions. Some measurements of lift-drag correlation were also made which indicated that essentially zero correlation exists in the turbulent field. It was concluded that the theory provides a reasonably accurate method of predicting the response of a slender structure to a turbulent wind. (Author)

Descriptors :   (*SLENDER BODIES, *GUST LOADS), (*CYLINDRICAL BODIES, *AEROELASTICITY), TURBULENCE, REYNOLDS NUMBER, BENDING, MOMENTS, MODEL TESTS, ANTENNAS, STRUCTURES, CANADA

Subject Categories : Aerodynamics
      Fluid Mechanics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE