Interferometric Investigations of Compressible Dynamic Stall Over a Transiently Pitching Airfoil
Abstract
The dynamic stall flow field over NACA 0012 airfoil pitching transiently from 0 - 60 deg at a constant rate under compressible flow conditions has been studied using the real-time technique of point diffraction interferometry. This investigation using nonintrusive diagnostics provides a quantitative description of the overall flow field, including the finer details of dynamic stall vortex formation, growth and the concomitant changes in the pressure distribution. Analysis of several hundred interferograms obtained for a range of flow conditions shows that the peak leading edge suction pressure coefficient that stall is nearly constant for a given free stream Mach number at all nondimensional pitch rates. Also, this value is below that seen in steady flow at static stall for the same Mach number, indicating that dynamic effects significantly effect the separation behavior. Further, for a given Mach number, the dynamic stall vortex seems to form rapidly at nearly the same angle of attack for all pitch rates studied
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 14, 1993
- Accession Number
- ADA268794
Entities
People
- L. W. Carr
- M. C. Wilder
- M. S. Chandrasekhara
Organizations
- American Institute of Aeronautics and Astronautics