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Ultra high bypass Nacelle aerodynamics inlet flow-through high angle of attack distortion testA flow-through inlet test program was conducted to evaluate inlet test methods and determine the impact of the fan on inlet separation when operating at large angles of attack. A total of 16 model configurations of approximately 1/6 scale were tested. A comparison of these flow-through results with powered data indicates the presence of the fan increased separation operation 3 degrees to 4 degrees over the flow through inlet. Rods and screens located at the fan face station, that redistribute the flow, achieved simulation of the powered-fan results for separation angle of attack. Concepts to reduce inlet distortion and increase angle of attack capability were also evaluated. Vortex generators located on the inlet surface increased inlet angle of attack capability up to 2 degrees and reduced inlet distortion in the separated region. Finally, a method of simulating the fan/inlet aerodynamic interaction using blockage sizing method has been defined. With this method, a static blockage device used with a flow-through model will approximate the same inlet onset of separation angle of attack and distortion pattern that would be obtained with an inlet model containing a powered fan.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Larkin, Michael J.
(Pratt and Whitney Aircraft East Hartford, CT, United States)
Schweiger, Paul S.
(Pratt and Whitney Aircraft East Hartford, CT, United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1992
Subject Category
Report/Patent Number
NAS 1.26:189149
Accession Number
Funding Number(s)
PROJECT: RTOP 535-03-10
Distribution Limits
Work of the US Gov. Public Use Permitted.
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