Abstract

"Formation flight has been known to provide performance benefits to migrating birds for over a century. Very optimistic estimates for the range extension experienced by migrating birds made in the 70?s prompted interest in implementing formation flight for range extension in civil and military aviation. Some successful implementations include the NASA AFF program and the DARPA/AFRL SAVE program where nearly 25% and 15% maximum drag reduction was achieved, respectively. In the literature, Computational Fluid Dynamics (CFD) has been applied to studying this potentially useful approach beyond what is feasibly possible through physical experimentation. However, due to the additional complexity associated with the parametric nature of this approach, CFD has been limited to lower order models such as vortex lattice methods, 3D-Euler simulation, and 3D Reynolds-Averaged Navier-Stokes (RANS) simulation. Indeed, this complexity is not strictly computational, as software limitations, preprocessing and postprocessing make using a more robust CFD methodology such as Large Eddy Simulation (LES) impractical. Therefore, we seek to address these challenges through a suite of CFD simulations using an open source, highly parallelized, CFD software capable of LES along with a ?low? code platform (EASA). We employ LES to determine the aerodynamic forces felt by two and three generic blended wing Unmanned Aerial Vehicles (UAVs) in cruise conditions as a function of their relative positioning and various flight parameters. Meanwhile the ?low? code platform (EASA) is used to allow the rapid batching of different cases, solution monitoring and rapid post-processing. The use of a ?low? code model deployment platform represents a novel means of democratizing not only a GUI-less, open-source engineering simulation software but also a means to democratize access to high-performance computing in general. The enhanced usability and productivity will be showcased. Finally, these results will be compared to a commercial CFD code such as ANSYS Fluent, along with cost and feature analyses between the two methods."