Within the scope of the national aviation research programme (projects KOMZELL, MUSIHC, COROS) the Institute has developed, in close cooperation with an industry partner, a coupled calculation environment, HOST/SIMPACK. This was to be able to better describe the rotor dynamic effects and transfer of time periodic loads from the rotating rotor system in the non-rotating fuselage using accurate mechanical models. The low-fidelity structure model used in the overall helicopter simulation is replaced by the SIMPACK-model, whereby the entire modelling bandwidth of modern multi-body simulations becomes available for the mapping of complex structures (CSD).
HOST, however, contains no interface for the exchange of structural data with external software in contrast to interfaces with CFD-solvers, which were already added a decade ago. The development of a HOST-CSD coupling is generally dependent on the realisation of suitable interfaces in the HOST-code, for which a deep understanding of its functionality is a prerequisite. In a first step, a demonstrator of the coupled trim calculation for models of isolated rotors is generated. For this, the HOST trim calculation was suitably modified. The schematic is illustrated in the figure below. Due to the periodic nature of the trim solution, a weak coupling is used, i.e. the coupling variables are exchanged for the overall rotor rotation in the frequency domain. Thus, on the multi-body programme side, increased post-processing is required while the solution is given in the temporal domain.