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Delta wing vortex manipulation using pulsed and steady blowing during ramp pitchingThe effectiveness of steady and pulsed blowing as a method of controlling delta wing vortices during ramp pitching has been investigated in flow visualization experiments conducted in a water tunnel. The recessed angled spanwise blowing technique was utilized for vortex manipulation. This technique was implemented on a beveled 60 delta wing using a pair of blowing ports located beneath the vortex core at 40% chord. The flow was injected primarily in the spanwise direction but was also composed of a component normal to the wing surface. The location of vortex burst was measured as a function of blowing intensity and pulsing frequency under static conditions, and the optimum blowing case was applied at three different wing pitching rates. Experimental results have shown that, when the burst location is upstream of the blowing port, pulsed blowing delays vortex breakdown in static and dynamic cases. Dynamic tests verified the existence of a hysteresis effect and demonstrated the improvements offered by pulsed blowing over both steady blowing and no-blowing scenarios. The application of blowing, at the optimum pulsing frequency, made the vortex breakdown location comparable in static and ramp pitch-up conditions.
Document ID
19960003150
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Moreira, J.
(Worcester Polytechnic Inst. MA, United States)
Johari, H.
(Worcester Polytechnic Inst. MA, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1995
Subject Category
Aerodynamics
Report/Patent Number
NASA-CR-199624
NIPS-95-05494
NAS 1.26:199624
AIAA PAPER 95-1817-CP
Accession Number
96N13159
Funding Number(s)
CONTRACT_GRANT: NAGW-4290
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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