A Time Correlator for Problems in Aerodynamics

Author: Skinner, George Tolmie

Year: 1955

Degree: Dissertation (Ph.D.)

Advisors: Liepmann, Hans Wolfgang; Lagerstrom, Paco A.; Roshko, Anatol

Committee Member: Unknown, Unknown

Option: Aeronautics; Physics

DOI: 10.7907/6B8H-3139

Abstract

An instrument, of fairly simple design, for measuring time correlation functions of two stationary random electrical signals is discussed. It is intended primarily for use in problems connected with aerodynamically produced acoustic fields, but has suitable properties for application to a rather wide range of aerodynamic problems involving turbulent fields. It has been designed and constructed with a view to economy, and simplicity of operation, and makes extensive use of the general statistical properties of the problems for which it is intended.

A few experimentally determined auto-correlation functions are given in order to indicate the degree of accuracy achieved, and the Fourier transform of the auto-correlation function of a random input is compared with the power-spectrum of the same function.

Some practical points of general interest are discussed.

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