Application of a Heterogeneous CFD Framework Towards Simulating Complete Rotorcraft Configurations

In the present work, a heterogeneous CPU-GPU framework, Mercury, is presented for simulations of complete helicopter configurations. Mercury incorporates three RANS flow solvers, 1) OverTURNS, a structured solver on CPUs, 2) HAMSTR, a line based unstructured solver on CPUs, and 3) GARFIELD, a structured solver on GPUs. The three solvers use the same mesh deformation module and communicate with the overset grid assembler (TIOGA) through a light-weight Python infrastructure. The framework allows seperate connectivity groups for reconnecting and stationary meshes to avoid unnecessary communication and accelerate simulations. The first of three cases presented is a transonic Caradonna-Tung rotor over a sphere, a simple case used for initial validation and load-balancing analysis. The second case presents a ROBIN fuselage with main rotor for comparison against unsteady pressure distributions measured in wind tunnel tests. The final case adds a notional tail rotor and hub to the ROBIN fuselage and rotor for interactional aerodynamic analysis of a full configuration.