Accurate rotor blade analysis is a complex task—requiring the consideration of the aerodynamics, motion and deformation of the rotor blade. The current paradigm is to employ two separate solvers, each adept at solving for a single physical phenomenon in the multi-physics problem. In this work, the fluid solver TAU and the solid solver CAMRAD II are coupled. TAU is highly specialized in solving fluid problems around complex geometries, while CAMRAD II describes elastic blade behavior and provides trimmed solutions. A rudimentary fluid-solid solver coupling between TAU and CAMRAD II has been developed at the Chair of Helicopter Technologies. However, the coupling is only intended for a single simulation case. As a result, the code is not designed to be modular, extensible or easy to use. Additionally, if this methodology would be used for future couplings, a unique adapter would be required for each simulation case.
Hence, this work focuses on the development of general adapters that support the “plug-and-play” of new solvers using the preCICE library. The structure of the adapter code is designed to be modular, using an Object-Oriented approach. The adapters minimize code dependencies between the two solvers and allow for the modular removal or addition of specific pre- or post-processing steps when passing data between solvers. Additionally, the TAU adapter allows the design and introduction of new simulation loops using the TAU-Python API.
Additional methods were implemented to supplement the preCICE library, which allowed for the passing of multiple timesteps of data in a single coupling step in a loosely-coupled simulation. Similarly, an intermediate interpolation step was implemented to allow for the 3D-1D passing of data from TAU to CAMRAD II.
Three cases were implemented using the adapter code. A simple, tightly-coupled simulation was used in the development of the TAU adapter as a proof of concept. In this case, the TAU adapter replaced the OpenFOAM adapter in an existing OpenFOAM-CalculiX coupling. The second case was a loosely-coupled rotor blade simulation with only rigid body motion, where we saw preliminary
convergence of TAU and CAMRAD II results. This simulation was extended to introduce elastic deformation in addition to rigid body motion to create a third case. The aim was to model elastic blade motion in the fluid simulation.
This work acts as a foundation for the TAU and CAMRAD II preCICE adapters, serving as a modular, extensible and easy to maintain codebase upon which other TAU or CAMRAD II fluid-structure interaction simulations can be developed. The adapter code also allows users to freely couple these two solvers with any other existing preCICE adapters and provides a standard interface to couple with new solvers in the future.
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Accurate rotor blade analysis is a complex task—requiring the consideration of the aerodynamics, motion and deformation of the rotor blade. The current paradigm is to employ two separate solvers, each adept at solving for a single physical phenomenon in the multi-physics problem. In this work, the fluid solver TAU and the solid solver CAMRAD II are coupled. TAU is highly specialized in solving fluid problems around complex geometries, while CAMRAD II describes elastic blade behavior and provides...
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