Based on structural mechanics

blade coupling flutter characteristics of an engine blisk were analyzed.Analyses of resonance rotating speed

coupling flutter and stall flutter were accomplished by swept fan rotor blade with small aspect ratio. The unusual phenomena showing that the change of dynamic and static frequencies of second-order and third-order on the swept fan blade with small aspect ratio were found

and recognized as another problem relating to coupling flutter. By structure adjustment of swept fan rotor blade with small aspect ratio

it was found that swept-forward blade was an important factor to this unusual phenomenon. Reducing the swept degree of the blade appropriately can avoid the possibility of flutter by design.It is suggested the separation of order frequency degree for the blade should satisfy the design requirement of 10%.