Fluid mechanics mechanisms in the stall process of airfoils for helicoptersPhenomena that control the flow during the stall portion of a dynamic stall cycle are analyzed, and their effect on blade motion is outlined. Four mechanisms by which dynamic stall may be initiated are identified: (1) bursting of the separation bubble, (2) flow reversal in the turbulent boundary layer on the airfoil upper surface, (3) shock wave-boundary layer interaction behind the airfoil crest, and (4) acoustic wave propagation below the airfoil. The fluid mechanics that contribute to the identified flow phenomena are summarized, and the usefulness of a model that incorporates the required fluid mechanics mechanisms is discussed.
Document ID
19810048375
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Young, W. H., Jr. (NASA Langley Research Center Hampton, Va., United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1981
Subject Category
Aerodynamics
Meeting Information
Meeting: Symposium on Numerical and Physical Aspects of Aerodynamic Flows