Abstract:

This paper examines the details of predicting the aerodynamic forces of a maneuvering helicopter rotor.A new approach to modeling the unsteady rotor aerodynamic forces is established based on the insight into the nonuniform induced velocity distribution,inflow dynamics and unsteady airfoil behavior.For a specified maneuver,the rotor control inputs and helicopter flight attitudes during the maneuvering are first obtained using an inverse solution technique.Then the unsteady rotor forces are numerically simulated by synthetically applying the vortex theory, dynamic inflow theory and unseady airfoil aerodynamic models.Good results of the sample calculations of lateral jink and pop up maneuvers are obtained.

Key words: helicop ters, maneuvering, ro to r, unsteady aerodynam ics