Multi-body dynamics has been one of the critical domains in the design and development of aerospace vehicles for many years. Few examples of multi-body dynamical systems relevant to aerospace engineering are: missile wing/fin deployment during flight, launch vehicle separation events, fluid-structures interaction, towed cables, etc. Usually, besides the complicated dynamics of these systems, they also include complex flow which is coupled with the motion of the system`s components. Traditionally these types of problems are not solved in a single simulation, but rather broken up into several different simulations and very often simplifying assumptions are made and large margins of safety are applied. In order to perform fully coupled CFD/Multi-body dynamic simulation, the software must have capabilities to model each aspect of the system of interest integrated into a single solver. In this work, a general interface, between ezair CFD code (from the Israeli CFD Center) and MotionGenesis multi-body dynamics code , was defined and allowed the incorporation of "infinite"-degrees-of-freedom (nDOF) simulation within the CFD environment. The method is first validated by simulating a rigid-body motion and comparing the results to the built-in rigid-body module. Then the method capabilities are demonstrated by three examples: (1) wing-flap flutter, (2) two-body towed system, and (3) wing deployment on a maneuvering body. This methodology enables engineers to accurately simulate the complex nature of aerospace dynamical system, without using simplifying assumptions.
