Validation of CFD Airdrop Simulations in the Vortical Wake of an Aircraft with Open Ramp

Abstract

During the first few seconds of an airdrop the supplies heavily interact with the wake of the military transport aircraft. Due to the particular shape of their rear fuselage and the voluminous landing gear fairings the flow field behind the aircraft is highly vortical. Flying in airdrop configuration even aggravates the situation. To comprehensively analyze and evaluate the airdrop capabilities of military transport aircraft DLR has developed a simulation approach, coupling the DLR TAU code with the multibody simulation tool SIMPACK. This Approach enables DLR to compute the trajectories of airdropped supplies under full consideration of flow interaction effects. For various cargo and cargo-parachute configurations DLR successfully demonstrated that this approach is well-suited to accurately compute an airdrop sequence. The results of two of these configurations are presented in this paper.