Effect of leading-edge curvature and slot geometry on dynamic stall control4

D. Greenblatt, I. Wygnanski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

The control of dynamic stall by periodic excitation was studied on NACA 0012 and 0015 airfoils under incompressible conditions, by means of twodimensional leading-edge excitation slots. Timeresolved surface pressure measurements were phaseaveraged and integrated to yield aerodynamic coefficients, and total drag was reduced from a wake survey. The dynamic bubble bursting mechanism, evident on the statically stalling NACA 0012 airfoil, was evident under dynamic conditions and its burst rate was controlled by the pitch-rate. Stall could be controlled by "trapping" the bubble upstream of the excitation slot location. In contrast, the NACA 0015 trailing-edge stall was controlled by a qualitative improvement in the pressure recovery. NACA 0012 dynamic stall was significantly more severe, typically requiring higher excitation amplitudes for effective control of the moment excursions. Furthermore, different reduced frequency ranges were found to be effective for the different airfoils. NACA 0015 control effectiveness was not proportional to Cμ, possibly due to the existence of centrifugal instabilities in the leading-edge region.

Original languageEnglish (US)
Title of host publication1st Flow Control Conference
StatePublished - Dec 1 2002
Externally publishedYes
Event1st Flow Control Conference 2002 - St. Louis, MO, United States
Duration: Jun 24 2002Jun 26 2002

Publication series

Name1st Flow Control Conference

Other

Other1st Flow Control Conference 2002
CountryUnited States
CitySt. Louis, MO
Period6/24/026/26/02

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ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Aerospace Engineering
  • Control and Systems Engineering

Cite this

Greenblatt, D., & Wygnanski, I. (2002). Effect of leading-edge curvature and slot geometry on dynamic stall control4. In 1st Flow Control Conference (1st Flow Control Conference).