Relative Motion Simulations Using an Overset Multi- mesh Paradigm With Kestrel v3

This paper documents the third version of an integrating product that allows cross-over between simulation of aerodynamics, dynamic stability and control, structures, propulsion, and store separation. The Kestrel software product is an integrating product written in modular form with a Python infrastructure to allow growth to additional capabilities as needed. Computational efficiency will also be improved by targeting the next generation peta-flop architectures envisioned for the 2010+ time frame. The need for Kestrel developed from the fact that existing computational resources (hardware and CSE software) are insufficient to generate decision data in a timely enough way to impact early-phase and even many sustainment phase acquisition processes. Kestrel is also targeted to the need of simulating multi-disciplinary physics such as fluid-structure interactions, inclusion of propulsion effects, moving control surfaces, and coupled flight control systems. The Kestrel software product is to address these needs for fixed-wing aircraft in flight regimes ranging from subsonic through supersonic flight, including maneuvers, multi-aircraft configurations, and operational conditions. Version 3.0 adds a relative motion capability for multiple bodies (e.g. aircraft store separation, aircraft cargo release). The relative motion capability utilizes PUNDIT, an implicit hole cutting domain connectivity component to calculate donor and receptor cells, as well as interpolation weights for data transfer between the respective meshes. Preliminary multi-mesh calculations are presented, as well as solutions to demonstrate improvements of the kAVUS solver for steady and unsteady simulations.