Development and Validation of a RANS-based Airdrop Simulation Approach

Abstract

During the first few seconds of an airdrop the payload interacts with the flow field behind the aircraft. As most airdrop simulation tools rely on simplified aerodynamic models, e.g. ones with frozen wind field information, DLR has developed an alternative simulation approach. It computes the aerodynamic interference effects during the initial phase of an airdrop and the resulting trajectory. To achieve this the DLR TAU flow solver has been coupled with the multi-body simulation software SIMPACK. The major advantage of this approach, apart from the fact that it does not rely on simplified aerodynamic models, is its multi-body functionality. Thus, the relative motion of bodies, for example between payload and parachute, can easily be examined as kinematic constraints are considered. DLR has successfully demonstrated that its airdrop simulation approach is well-suited to predict the trajectories of different cargo and cargo--parachute configurations. An overview on the methodology, the verification and validation of this approach is presented in the following.