In this thesis analysis and design of helicopter rotor blades were discussed for reduced
vibrational level. For this purpose an optimization procedure was developed which involves
coupling of the comprehensive rotorcraft analysis tool CAMRAD JA and the gradient based
optimization algorithm. The main goal was to achieve favorable blade structural dynamics
characteristics that would lead to reduction in vibrational level. For this purpose blade
stiffness and mass distributions were considered as the design variables. In order to avoid
likely occurrences of unrealistic results, the analyses were subjected to constraints which
were sensitive to the design variables. The optimization procedure was applied on two
isolated rotor blades and a full helicopter with main rotor, tail rotor and fuselage by using
natural frequency separation and hub load minimization respectively. While the former
approach relied on the blade natural frequencies, the latter approach involved higher
harmonic aerodynamic and blade motion calculations. For both approaches, the
improvement in vibration characteristics and blade mass and stiffness distributions of the
initial design and the design after optimization analyses were compared and discussed.
Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613661/index.pdf |
Date | 01 September 2011 |
Creators | Tamer, Aykut |
Contributors | Yaman, Yavuz |
Publisher | METU |
Source Sets | Middle East Technical Univ. |
Language | English |
Detected Language | English |
Type | M.S. Thesis |
Format | text/pdf |
Rights | To liberate the content for public access |
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