Physics-Based Airframe Design Approach Expanded from the Conceptual Design of Coaxial Rotorcraft

Unconventional configurations are required to satisfy the existing niche in conventional rotorcraft owing to the increasing demands for high-speed rotorcraft operations. Thus, this study proposes a physics-based airframe design procedure for an unconventional rotorcraft, aiming to integrate the physical basis into the conceptual design and the subsequent airframe structure while maintaining an efficient design cycle. The procedure encompasses the conceptual and preliminary design stages, including the baseline configuration determination, weight estimation, airframe internal structural design, and structural robustness evaluation. The structural robustness of the airframe is assessed through the static structural, modal, and harmonic analyses, considering the appropriate load conditions and constraints. Therefore, the study findings provide design guidelines for the development of airframe structure, which in turn can contribute to the enhancement of stability in rotorcraft design.