Numerical simulation of noise propagation in jet engine ducts
by Kenneth J. Baumeister and Edward C. Bittner.

Description

Main Author

Baumeister, Kenneth J.

Related Names

Bittner, Edward C.
United States. National Aeronautics and Space Administration.
Lewis Research Center.

Language(s)

English

Published

Washington, D.C. : National Aeronautics and Space Administration ; 1973.

Subjects

Airplanes > Airplanes / Turbofan engines > Airplanes / Turbofan engines / Noise > Airplanes / Turbofan engines / Noise / Mathematical models.
Airplanes > Airplanes / Air ducts > Airplanes / Air ducts / Noise > Airplanes / Air ducts / Noise / Mathematical models.

Summary

A finite difference formulation is presented which is useful in the study of acoustically treated inlet and exhaust ducts used in turbofan engines. The difference formulation can readily handle acoustic flow field complications, such as axial variations in wall impedance and cross-sectional area, that would occur in a sonic inlet. In formulating the difference solutions, the continuous acoustic field is lumped into a series of grid points spread uniformly throughout the field. At each point, the pressure is separated into its real and imaginary terms. Example solutions are presented for sound propagation in a one-dimensional straight hard-wall duct and in a two-dimensional straight soft-wall duct without steady flow.

Note

Prepared at Lewis Research Center.
Cover title.

Physical Description

iii, 46 p. : ill. ; 27 cm.

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