Toolchain for free flight measurement and code validation purposes - Test and evaluation session

During the development of new numerical methods or in the validation process of a computational tool for a specific aerodynamic phenomenon, the comparison with experimental data is compulsory. Especially in helicopter aeromechanics, often experimental data is not available in the required depth or is very expensive to conduct. To overcome the lack of data the Institute of Aerodynamics and Gasdynamics (IAG) at the University of Stuttgart has developed a flying measurement platform. This model helicopter is able to collect the necessary flight test data on a model scale. These tests are embedded in a modular tool chain, which serves for validation purposes of the used fluid-structure coupling at IAG. In this tool chain the raw experimental data is obtained with the model helicopter and post-processed with a Kalman-filter. Numerical setups were built up to compute the structural dynamics and flight dynamics with the commercial comprehensive code CAMRAD II, and the fluid dynamics with the FLOWer flow solver. A coupling process assures that a free flight trim of the complete helicopter with elastic main rotor blades is computed. As an example, a free flight of the helicopter in ground proximity is regarded and results are shown.

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