Flutter of swept fan blades.

The effect of sweep on fan blade flutter by applying the analytical methods developed for aeroelastic analysis of advanced turboprops was studied. Two methods are used. The first method utilizes an approximate structural model in which the blade is represented by a swept, nonuniform beam. The second method utilizes a finite element technique to conduct modal flutter analysis. For both methods, the unsteady aerodynamic loads are calculated using two dimensional cascade theories that are modified to account for sweep. An advanced fan stage is analysed with 0, 15, and 30 deg. of sweep. It is shown that sweep has a beneficial effect on predominantly torsional flutter and a detrimental effect on predominantly bending flutter. This detrimental effect is shown to be significantly destabilizing for 30 deg. of sweep. (A)

Duke Scholars

Author Robert Kielb Thomas Lord Department of Mechanical Engineering and Materia ...