Title

The Use Of Acoustic Scale Models For Investigating Near Field Noise Of Jet And Rocket Engines

Date

1961

Index Abstract

Contrails and DTIC condensed

Photo Quality

Incomplete

Report Number

WADD TR 61-178

Creator

Morgan, Walter V.

Young, Kenneth J.

Sutherland, L. C.

Corporate Author

The Acoustics Group, Aero-Space Division, Boeing Airplane Company

Laboratory

Flight Dynamics Laboratory

Extent

100

Identifier

AD0268576

AD0268576

Access Rights

OTS

Distribution Classification

1

Contract

AF 33(616)-6834

DoD Project

1370

DoD Task

13786

DTIC Record Exists

Yes

Distribution Change Authority Correspondence

None

Report Availability

Full text available

Date Issued

1961-04

Abstract

Analytical and experimental studies have been made to examine the feasibility of using acoustic scale models for near field noise investigations. Analyses show that the important characteristics of noise generation, propagation, and measurement can be scaled. A relatively few deviations from this involve small errors which are generally negligible in the near field. The most straightforward model is seen to be one which duplicates the gas flow parameters of the full scale engine. The validity of such models has been demonstrated by a series of tests for a wide variety of nozzle exit conditions, from turbojet through rocket exhausts, and whether in a free field or in the presence of objects which interfere with the flow, such as shaped nozzles and flame deflectors. It is further determined both analytically and experimentally that models, in certain cases, may be simplified without impairing the results of a scaled test. Considerations in simplifying a model include: reduction of the nozzle size; absence or presence of reflecting surfaces; use of fewer than the full scale number of engines; and use of a substitute gas which is different from and at a lower temperature than that in the full scale engine.

Publisher

Wright-Patterson Air Force Base, OH : Aeronautical Systems Division, Air Force Systems Command, United States Air Force

Distribution Conflict

No

Provenance

IIT

Type

report

Subject

Measurement

Rocket Engine Noise

Noise Generators

Jet Engine Noise

Model Tests

Exhaust Nozzles

Rocket Engines

Flame Arresters

Fluid Flow

Nozzles

Scale

Jet Engines

Simulation

Acoustics

Format

1 online resource