VARIABLE PITCH TURBOFAN ENGINE AND A METHOD FOR OPERATING SAME

摘要

Variable geometry guide vanes are provided in a variable pitch turbofan assembly. A method is disclosed for reducing aerodynamically induced stresses in the variable pitch fan blades as the blades are changed between the forward and reverse pitch modes. The guide vane geometry is scheduled to change in a manner to control the flow into and out of the fan blades in order to establish a favorable aerodynamic environment during the transition between the forward and the reverse pitch modes.