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Crossflow effects on steady and fluctuating pressures on an ogive-cylinder cone-frustum model in supersonic separated flowWind-tunnel tests were conducted on an ogive-cylinder model with two axisymmetric protuberances having cone frustum angles of cone = 23 deg and 45 deg that were used to generate detached shock waves and the resulting separated flow areas downstream of the shock. The tests were conducted in a 9 by 7 foot supersonic wind tunnel at a free-stream Mach number of 2.0 and at Reynolds numbers of 1.5 x 1 million and 3.9 x 1 million, based on body diameter. The model had an afterbody fineness ratio of 8.3, and the ogive nose had a fineness ratio of 3.0. Two characteristics of the fluctuating pressures in surface vortex flows that result from the crossflow component, (velocity along the tunnel longitudinal axis free stream angle of attack), in combination with changes in the longitudinal pressure gradient were measured: (1) the broadband, rms-pressure coefficients and (2) the power spectral densities. Measurements are presented for various flow regions on the model such as the attached turbulent boundary layer, the detached frustum shock wave, and separated flow areas. The results indicate that the pressure fluctuations around or in the neighborhood of the foci of the vortex flows had broadband intensities and power spectral densities nearly identical to the levels previously measured in separated-flow regions at angles of attack of 0 deg.
Document ID
19820005235
Acquisition Source
Legacy CDMS
Document Type
Technical Publication (TP)
Authors
Dods, J. B., Jr.
(Raman Aeronautics Research and Engineering, Inc., Palo Alto Calif., United States)
Coe, C. F.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
September 4, 2013
Publication Date
November 1, 1981
Subject Category
Aerodynamics
Report/Patent Number
A-8563
NASA-TP-1951
Accession Number
82N13108
Funding Number(s)
PROJECT: RTOP 505-31-31
CONTRACT_GRANT: NAS2-10139
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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