Rough Design Criterion for Ground and Air Resonance of Helicopter Rotor with Three or More Blades
1989 Volume 37 Issue 422 Pages 155-158
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1989 Volume 37 Issue 422 Pages 155-158
The rough criterion for the ground or air resonance of helicopter rotor with three or more blades, which was presented by Donham et al. in 1969, is simple and useful. The theoretical basis is however not so clear. It is the purpose of this paper to assign some theoretical reasons for the criterion. The Coleman's theory is reviewed, and then a concept of “Quasi-Resonance-Center” is defined. Then it is found that the “Resonance Region” designated by Donham et al. is the above “Quasi-Resonance-Center” and nothing but.
