Tilt Rotor Performance Enhancement Through Variable Twist Control

Tilt rotor aircraft are required to operate in flight conditions ranging from hover and low speed edgewise flight to high speed cruise. It is not possible to achieve optimal performance in all flight conditions with rotor blades with a fixed twist distribution. The goal of this project is to conduct a design assessment of variable twist rotor systems that will allow in-flight adjustment of blade twist. Newly developed rotor design optimization software will be used to determine performance characteristics and optimum twist distributions for representative tilt rotor flight conditions and to quantify the required amount and distribution of the variable twist. Implementation of a variable twist capability will be explored using recent developments in advanced actuation technology, including shape memory design concepts involving variable twist more readily relaizable. The candidate rotor blade designs will be evaluated with input from experienced tilt rotor design personnel from industry to ensure that the final variable twist system can meet realistic performance, structural, and manufacturability criteria. The end result will be a variable twist rotor blade design well suited for detailed simulation and assessment in Phase II.