CFD-based Simulation and Experiment in Helicopter Aeromechanics

Accurate simulation of the aeromechanics of helicopters poses significant challenges. Satisfactory agreement between the predictions of numerical models and experimental data requires that the model successfully capture a broad range of complex physical interactions between the aerodynamics and the mechanics of the system. In most practical cases, the physical processes at work cannot be determined uniquely from the data at hand, reducing the process of constructing an accurate simulation to one of educated guesswork. On the basis that improved simulation fidelity might be obtained simply through improved modelling of isolated aspects of the physics of the problem, a helicopter aeromechanics simulation model was constructed in which the physical realism of the model of the helicopter wake could be varied. Experiences in validating this numerical test bed against real-world data, from both flight test and laboratory experiments, are generalised into set of more widely-applicable observations regarding the relationship between complex dynamic models and the physical reality that they are supposed to represent.