cantilever fan blade
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CG: n

CT: The fundamental and lowest frequency natural modes in a cantilever fan blade exhibit significant amounts of flexure and torsion coupled by pretwist and operation in a rotational force field. Consequently the flutter estimation of such blades requires an accurate structural description that incorporates these two effects, amongst others. A beam-type finite element model is used in this study with up to six span wise elements, each element being pretwisted. Coalescence-type flutter is found with subsonic aerodynamics. Evidence of the aerodynamic resonance phenomenon is exhibited and the importance of including radially varying aerodynamic forces is brought out.

S: NASA-AMRDEC (offline)

N: 1. – cantilever (n): “projecting block or bracket from a building supporting a molding, balcony, etc.,” 1660s, probably from cant (n.2) + lever, but earliest form (c. 1610) was cantlapper. First element also might be Spanish can “dog,” architect’s term for an end of timber jutting out of a wall, on which beams rested. Related: Cantilevered.
– fan (n): device to make an air current, Old English fann (West Saxon) “a basket or shovel for winnowing grain” (by tossing it in the air), from Latin vannus, perhaps related to ventus “wind” (see wind (n.1)), or from PIE root *wet- (1) “to blow” (also “to inspire, spiritually arouse”). Old English did not have a letter -v-, hence the change in the initial consonant.
– blade (n): Old English blæd “a leaf,” also “a leaf-like part” (of a spade, oar, etc.), from Proto-Germanic *bladaz (source also of Old Frisian bled “leaf,” German Blatt, Old Saxon, Danish, Dutch blad, Old Norse blað), from PIE *bhle-to-, suffixed form (past participle) of root *bhel- (3) “to thrive, bloom.”
2. The fundamental and lowest frequency natural modes in a cantilever fan blade exhibit significant amounts of flexure and torsion coupled by pretwist and operation in a rotational force field. Consequently the flutter estimation of such blades requires an accurate structural description that incorporates these two effects, amongst others. A beam-type finite element model is used in this study with up to six spanwise elements, each element being pretwisted. Coalescence-type flutter is found with subsonic aerodynamics. Evidence of the aerodynamic resonance phenomenon is exhibited and the importance of including radially varying aerodynamic forces is brought out.

S: 1. OED – https://bit.ly/33pkB5M; https://bit.ly/2IHmrHD; https://bit.ly/2VDyURJ (last access: 10 October 2019). 2. RG – https://www.researchgate.net (last access: 10 October 2019).

SYN: fan blade (depending on context)

S: GDT – https://bit.ly/2B13f30 (last access: 11 October 2019); TERMIUM PLUS – https://bit.ly/35odD2V (last access: 11 October 2019).

CR: actuator, sonic nozzle.