Accession Number:

AD0707939

Title:

THE RESPONSE AND AIRLOADING OF HELICOPTER ROTOR BLADES DUE TO DYNAMIC STALL

Descriptive Note:

Technical rept.

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE AEROELASTIC AND STRUCTURES RESEARCH LAB

Personal Author(s):

Report Date:

1970-05-01

Pagination or Media Count:

48.0

Abstract:

An aerodynamic model is constructed for the application of the properties of dynamic stall of airfoils to the calculation of the airloads and blade motion of helicopter rotor blades. Dynamic stall occurs on an airfoil undergoing pitching motion at high angle of attack, and is characterized by peak section lift and moment much larger than the corresponding static stall loads. A method is developed for the solution of the equations of motion of a rotor blade by means of harmonic analysis. The effect of dynamic stall on the blade torsional motion at high advance ratio is examined, and comparison is made with the limited experimental data available. An increase in the dynamic stall angle is shown to significantly decrease the amplitude of the pitch motions.

Subject Categories:

  • Aerodynamics
  • Helicopters

Distribution Statement:

APPROVED FOR PUBLIC RELEASE