Accession Number:

AD0752169

Title:

An Expansion Scheme for the Noise from Circular Jets,

Descriptive Note:

Corporate Author:

DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V BERLIN (WEST GERMANY)

Personal Author(s):

• Michalke,Alfons

Report Date:

1971-10-13

Pagination or Media Count:

10.0

Abstract:

An expansion scheme for the noise from circular jets is derived which takes account of the geometrical configuration of circular jets and of recent observations of jet turbulence. It is found that only a relatively small number of turbulence components, characterized by their frequency and azimuthal wave-number, contribute essentially to the far-field noise. A jet thickness parameter and a convection parameter strongly influence the sound radiation. Most of the phenomena of jet noise known from experiments can be explained by this very general solution. Theoretical results derived previously by means of the eddy model of turbulence are also contained in the present solution. These results are special, since they were obtained under very restricting assumptions. Author

Descriptors:

• *AERODYNAMIC NOISE
• JET FLOW
• TURBULENCE
• VORTICES
• INTENSITY
• CLASSIFICATION
• STATISTICAL PROCESSES

Subject Categories:

• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE