Accession Number : AD0862129

Title :   The Effect of High Intensity Turbulence on the Aerodynamics of a Rigid Circular Cylinder at Subcritical Reynolds Number,

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

Personal Author(s) : Surry, D.

Report Date : OCT 1969

Pagination or Media Count : 204

Abstract : The interaction of high intensity turbulence with the flow past a rigid circular cylinder was studied experimentally at subcritical Reynolds numbers. Grids were used to produce homogeneous turbulence fields with longitudinal scales ranging from 0.36D to 4.40D, and with longitudinal intensities greater than 10%. Power and cross-spectra of the turbulence components (the 'system input') were measured in order to carefully define the turbulence characteristics. A model with which measurement of arbitrary two-point pressure correlations could be made was used in the response experiments. Subsequent integrations yielded the spectral properties of the unsteady drag and lift. Measurement of mean drag and Strouhal frequency indicate that to some extent even severe large-scale turbulence can be considered equivalent to an increase in the effective Reynolds number. Vortex shedding is not disrupted drastically by severe turbulence, but is affected more by that at low frequency than at high. The unsteady lift response is still dominated by the vortex shedding, whereas the unsteady drag is primarily a response to turbulence. (Author)

Descriptors :   *TURBULENCE), (*GUST LOADS, CYLINDRICAL BODIES), (*CYLINDRICAL BODIES, REYNOLDS NUMBER, INTENSITY, WIND, STRUCTURES, AIRCRAFT, MODEL TESTS, DRAG, LIFT, VORTICES, CANADA.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE