Compressible dynamic stall control using high momentum microjets

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Authors
Beahan, James J.
Shih, Chiang
Krothapalli, Anjaneyulu
Kumar, Rajan
Chandrasekhara, Muguru S.
Subjects
Advisors
Date of Issue
2014
Date
2014
Publisher
Language
Abstract
Control of the dynamic stall process of a NACA 0015 airfoil undergoing periodic pitching motion is investigated experimentally at the NASA Ames compressible dynamic stall facility. Multiple microjet nozzles distributed uniformly in the first 12 % chord from the airfoil’s leading edge are used for the dynamic stall control. Point diffraction interferometry technique is used to characterize the control effectiveness, both qualitatively and quantitatively. The microjet control has been found to be very effective in suppressing both the emergence of the dynamic stall vortex and the associated massive flow separation at the entire operating range of angles of attack. At the high Mach number (M = 0.4), the use of microjets appears to eliminate the shock structures that are responsible for triggering the shock-induced separation, establishing the fact that the use of microjets is effective in controlling dynamic stall with a strong compressibility effect. In general, microjet control has an overall positive effect in terms of maintaining leading edge suction pressure and preventing flow separation.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.1007/s00348-014-1813-6
Series/Report No
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
NASA Ames
Format
11 p.
Citation
Exp Fluids (2014) 55:1813
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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