SIMULATION OF MANEUVERING FLEXIBLE AIRCRAFT BY COUPLED MULTIBODY/CFD

This paper illustrates the application of Multibody SystemDynamics (MSD) cou- pled to Computational Fluid Dynamics (CFD) for the aeroelas tic analysis of detailed aircraft models undergoing arbitrary free flight motion. Computatio nal AeroServoElasticity (CASE) requires the concurrent modeling of rather different aspec ts of aeromechanics, including rigid body dynamics, structural flexibility, fluid flow, servo-mechanisms for actuators. Considering all these issues within a single monolithic solver is partic ularly difficult, and possibly not worth the effort. An efficient alternative consists in building CASE modeling capability using inde- pendently developed software for each single domain: struc ture, fluid and mechanism analysis. The partitioned approach relies on dedicated software base d on the most appropriate techniques to address the dynamics of each specific field. Efficiency is guaranteed since each subsystem can be modeled independently and only the time and spatial sc ales of interest are considered. Another advantage is the great flexibility in setting up the m odel: the designer can indeed choose the most appropriate tools, trading accuracy for com putational costs, demanding for higher-order fidelity methods only when simplified ones cannot be applied, or their validation is required. The outcome of the combination of Multibody Sys tem Dynamics (MSD) and Com- putational Fluid Dynamics (CFD) is a prediction tool with a h level of accuracy, that can be crucial in the preliminary and intermediate design steps ofunconventional configurations, for the investigation of loads, performance, stability and vib ratory response of the vehicle at the boundaries of the flight envelope.