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Investigation of passive shock wave-boundary layer control for transonic airfoil drag reductionThe passive drag control concept, consisting of a porous surface with a cavity beneath it, was investigated with a 12-percent-thick circular arc and a 14-percent-thick supercritical airfoil mounted on the test section bottom wall. The porous surface was positioned in the shock wave/boundary layer interaction region. The flow circulating through the porous surface, from the downstream to the upstream of the terminating shock wave location, produced a lambda shock wave system and a pressure decrease in the downstream region minimizing the flow separation. The wake impact pressure data show an appreciably drag reduction with the porous surface at transonic speeds. To determine the optimum size of porosity and cavity, tunnel tests were conducted with different airfoil porosities, cavities and flow Mach numbers. A higher drag reduction was obtained by the 2.5 percent porosity and the 1/4-inch deep cavity.
Document ID
19820014335
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Nagamatsu, H. T.
(Rensselaer Polytechnic Inst. Troy, NY, United States)
Brower, W. B., Jr.
(Rensselaer Polytechnic Inst. Troy, NY, United States)
Bahi, L.
(Rensselaer Polytechnic Inst. Troy, NY, United States)
Ross, J.
(Rensselaer Polytechnic Inst. Troy, NY, United States)
Date Acquired
September 4, 2013
Publication Date
April 1, 1982
Subject Category
Aerodynamics
Report/Patent Number
NAS 1.26:168844
NASA-CR-168844
Accession Number
82N22209
Funding Number(s)
CONTRACT_GRANT: NSG-1624
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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