Accession Number:

AD0694071

Title:

ACOUSTIC MEASUREMENTS IN SUPERSONIC TRANSITIONAL BOUNDARY LAYERS

Descriptive Note:

Final rept. 30 Jul-26 Sep 1968

Corporate Author:

ARO INC ARNOLD AFS TN

Personal Author(s):

• Pate, S. R.
• Brown, M. D.

Report Date:

1969-10-01

Pagination or Media Count:

36.0

Abstract:

Surface pressure fluctuations associated with transitional and turbulent boundary-layer flows on a sharp, slender cone at supersonic Mach numbers were experimentally investigated in a 40- by 40-in. supersonic wind tunnel using a flush-mounted 0.25-in.-diam microphone. The results at Mach numbers 3 and 4 demonstrate the feasibility of locating microphones onboard wind tunnel test models to measure overall pressure fluctuations and power spectral distributions in transitional and fully developed turbulent flows. Transition Reynolds numbers determined using a surface microphone are compared with two other established methods of detection. Selected boundary-layer pressure fluctuation characteristics power spectral density and root-mean-square values and transition profiles are presented. Methods of data acquisition and analysis are discussed.

Descriptors:

• *BOUNDARY LAYER TRANSITION
• *CONICAL BODIES
• *TURBULENT BOUNDARY LAYER
• AERODYNAMIC NOISE
• FEASIBILITY STUDIES
• MICROPHONES
• POWER SPECTRA
• PRESSURE
• REYNOLDS NUMBER
• SLENDER BODIES
• SUPERSONIC CHARACTERISTICS
• SURFACE PROPERTIES
• WIND TUNNEL MODELS

Subject Categories:

• Aerodynamics
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE