Advancing State-of-the-Art Unsteady, Multidisciplinary Rotorcraft Simulations

To address the complex multidisciplinary nature of rotorcraft analysis, high-fidelity computational fluid and structural dynamics models have been developed to investigate a range of challenging rotorcraft issues. First, an advanced technology, active flap rotor (Boeing SMART) is investigated, and performance, aerodynamic and structural loads, vibration, noise prediction and flow physics mechanisms are shown. The rotor model includes complex and detailed flap and flap-gap modeling. Second, analyses on an advanced dynamics model (ADM) research configuration rotor investigate regressing lag mode (RLM) aero elastic instabilities. Tightly-coupled computational fluid dynamics (CFD)/computational structural dynamics (CSD) stability calculations show noticeable improvement over lower fidelity methods. Third, the state-of-the-art capability of CFD methods to directly predict low frequency in-plane noise on realistic lifting rotors is benchmarked for the first time. In all cases, comparisons are made between CFD/CSD, comprehensive analyses, and experimental data. Taken together, these works offer an important advancement in rotorcraft analysis capability for advanced technology rotor configurations under study for future Army rotorcraft, and highlight future needs in next-generation rotorcraft analysis software.