Integrated multidisciplinary design optimization of rotorcraft

: This paper describes a joint NASA/Army research activity at the Langley Research Center to develop optimization procedures aimed at improving the rotor blade design process by integrating appropriate disciplines and accounting for important interactions among the disciplines. The activity is being guided by a Steering Committee made up of key NASA and Army researchers and managers. The committee, which has been named IRASC (Integrated Rotorcraft Analysis Steering Committee). has defined two principal foci for the activity: a white paper which sets forth the goals and plans of the effort; and a rotor design project which will validate the basic constituents, as well as the overall design methodology for multidisciplinary optimization. The paper describes the optimization formulation in terms of the objectives function, design variables, and constraints. The analysis aspects are discussed, and an initial attempt at defining the interdisciplinary coupling is summarized. At this writing, some significant progress has been made. Results are given in the paper which represent accomplishments in rotor aerodynamic performance optimization for minimum hover horsepower, rotor structural optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight.