Vadim Yu.Eremin, Sergei E.Paryshev
DOI Number: N/A
Conference number: IFASD-2015-105
The task to provide multi-disciplinary engineering analysis of helicopter rotor blade is stated, as the most vital, in authors‟ opinion, to provide efficiency of the design process, where it is just the efficiency rather than deep insight into any of the discipline that has to be preferred. Two contributing problems are considered within this task formulation: A combined analytical/experimental method to get Campbell‟s diagram for a helicopter blade has been developed. The method is based on experimental measurement of elastic compliance matrix of the blade at zero rotation speed. Results for actual blades are presented. The vital demand of the task of blade characteristics identification goes from the fact that to get Campbell‟s diagram and vibration mode shapes of a rotating blade from appropriate dynamic response processing is rather a complicated problem; also any hardware to excite the blade under rotation may affect properties of the mechanical system and thus deteriorate the results. A problem of computational analysis of blade motion within the rotor is formulated, for which dynamic condensation approach is NOT used. For aerodynamic analysis, a discrete singularities method is used that makes it possible to calculate chord-wise aerodynamic forces exactly. Also under discussion is the use of undeservedly forgotten abstract concepts like “suction force” and “chordwise variable inductive wash” closely associated with the theory of thin lifting surface.