NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Measurements of fluctuating pressure in a rectangular cavity in transonic flow at high Reynolds numbersAn experiment was performed in the Langley 0.3 meter Transonic Cryogenic Tunnel to study the internal acoustic field generated by rectangular cavities in transonic and subsonic flows and to determine the effect of Reynolds number and angle of yaw on the field. The cavity was 11.25 in. long and 2.50 in. wide. The cavity depth was varied to obtain length-to-height (l/h) ratios of 4.40, 6.70, 12.67, and 20.00. Data were obtained for a free stream Mach number range from 0.20 to 0.90, a Reynolds number range from 2 x 10(exp 6) to 100 x 10(exp 6) per foot with a nearly constant boundary layer thickness, and for two angles of yaw of 0 and 15 degs. Results show that Reynolds number has little effect on the acoustic field in rectangular cavities at angle of yaw of 0 deg. Cavities with l/h = 4.40 and 6.70 generated tones at transonic speeds, whereas those with l/h = 20.00 did not. This trend agrees with data obtained previously at supersonic speeds. As Mach number decreased, the amplitude, and bandwidth of the tones changed. No tones appeared for Mach number = 0.20. For a cavity with l/h = 12.67, tones appeared at Mach number = 0.60, indicating a possible change in flow field type. Changes in acoustic spectra with angle of yaw varied with Reynolds number, Mach number, l/h ratios, and acoustic mode number.
Document ID
19920016509
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Tracy, M. B. (NASA Langley Research Center Hampton, VA, United States)
Plentovich, E. B. (NASA Langley Research Center Hampton, VA, United States)
Chu, Julio (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1992
Subject Category
Aerodynamics
Report/Patent Number
NAS 1.15:4363
NASA-TM-4363
L-16859
Accession Number
92N25752
Funding Number(s)
PROJECT: RTOP 505-68-70-08
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available