Peak statistics and narrow-band features of coupled torsion-flapping rotor blade vibrations to turbulence
✍ Scribed by G.H. Gaonkar
- Publisher
- Elsevier Science
- Year
- 1974
- Tongue
- English
- Weight
- 838 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
This study concerns the peak statistics and the narrow-band features of coupled torsionflapping rotor blade responses during high advance rat io flight regimes when blade vibrations due to atmospheric turbulence can be very severe. The peak statistics of torsion and flapping include the total peak rate expectations, the probability density function for the height of a local peak conditional on the occurrence of a peak for this instantaneous blade azimuth position, and the probability density function of peak magnitude over one rotor revolution. These peak density results are also compared with other approximate formulae based on (a) certain narrow band approximations, (b) the Rayleigh and the time-averaged Rayleigh density laws, and (c) the single degree of freedom models without torsion-flapping coupling. While this coupling can appreciably influence certain narrow band features of flapping and has a detrimental effect on the probability of high-level torsional excursions, it has negligible effect on flapping excursions and on the narrow band features of torsion.