Aeroelastic analyses of an unmanned helicopter

Date

2023-4-14

Author

Uzunkaya, Alaaddin Furkan

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In helicopter comprehensive analysis tools, helicopter blades could be modeled as rigid beams in torsional direction; however, it is well known that helicopter blades are very flexible structures. One of the main purposes of this thesis is to analyze the effects of torsional twist on the helicopter’s performance characteristics and to examine validity of rigid blade assumption. To perform the analyses, aerodynamic loads are calculated by using blade element momentum theory. In elastic blade analyses, aerodynamic loads cause a torsional twist which increments aerodynamic load field on the blade. On the other hand, there is no torsional twist and aerodynamic load increment in the rigid blade assumption. A trim code is written to obtain trim points for a level flight at sea level by using rigid and elastic blade in which the only difference is the torsional twist and aerodynamic increments due to the torsional twist. In the second part of the thesis, flutter analyses are conducted for the reference blade by using steady aerodynamic loads, Theodorsen’s, Loewy’s and a modified version of Loewy’s unsteady aerodynamic theories.

Subject Keywords

Aeroelasticity, Unmanned helicopter, Flutter, Theodorsen, Loewy

URI

https://hdl.handle.net/11511/103097

Collections

Graduate School of Natural and Applied Sciences, Thesis