Accession Number : AD0483554

Title :   AEROELASTIC PROBLEMS IN AN ANTENNA VIBRATION PROJECT.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Mortenson, William Peter

Report Date : MAY 1966

Pagination or Media Count : 64

Abstract : Continued studies were made of bluff body separation and its effect upon the response of an aeroelastic model for a range of tunnel air speeds and model cross sections. The motivation for this work was the application to the antenna element vibration problem as posed in the various Wullenwebber type antenna installations operated by the United States Navy throughout the world. A retrofit configuration change was devised to significantly decrease the wind induced response of the long horizontal boom boards. Although flow separation still exists, the character of the aerodynamic forcing function has been modified such that the energy spectra has apparently been broadened from a single dominant peak into many weaker peaks. Thus the effective total response is reduced. The digital data processing has been extended in scope due to the repeatability in signal analysis. Estimates have been made of the two dimensional random input forcing function using the output response in conjunction with the aeroelastic model transfer function. Reasonably good results were obtained and an estimate was made of the root mean square value of the unsteady fluctuating air load. (Author)

Descriptors :   (*AEROELASTICITY, ANTENNAS), (*ANTENNAS, AERODYNAMIC CHARACTERISTICS), BLUNT BODIES, TURBULENCE, WIND TUNNELS, FLUID MECHANICS, VIBRATION, LIFT, DRAG, SUBSONIC FLOW, VORTICES, EQUATIONS.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE