Aerodynamic Damping of Vibrating Helicopter Rotors.
Abstract
An experimental and theoretical study of aerodynamic damping of a hingeless helicopter rotor harmonically excited in heave in one of several bending modes is presented. Experimental damping data is given for rotor pitch angles of 0, 1 and 5 degrees. At each pitch angle, damping data is presented for a wide range of the oscillation to rotational frequency ratio, m. Rotor structural damping as a function of rpm is also determined so an accurate measure of aerodynamic contributions to total rotor damping is obtained. Theoretical aerodynamic damping is determined by treating the model rotor as a multi-degree of freedom system wherein the structural and aerodynamic properties of the rotor are treated as a series of finite structural elements and a series of two-dimensional strip theory aerodynamic panels. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1974
- Accession Number
- AD0775929
Entities
People
- J. E. Johnson
- J. F. Unruh
- R. L. Bass Iii
Organizations
- Southwest Research Institute