Noise Characteristics of Turbojet Engines in Test Cells

A number of comprehensive acoustical surveys of several turbojet engine test facilities have recently been completed. Preliminary results of these surveys, including data on the noise characteristics of turbojet engines operating in test cells are discussed. Sound pressure level spectra are presented for several different present-day turbojet engines at various engine operating conditions. Problems introduced in the interpretation of test cell measurements because of the nature and complexity of the turbojet engine noise source are discussed.