A brief survey of dynamic inflow models and free wake methods has been conducted from the perspective of real-time flight simulation in a realistic environment such as helicopter-ship operations. In their basic form, inflow models do not take wake distortion dynamics into account. Most extensions contain a gain that set the strength of the distortion effect, for which different researchers found different values. Therefore, without validation against experimental data, the added value of wake distortion dynamics models is quite low. The effect of ground proximity on the inflow at the rotor disk has been modelled by finite-state models too, but even the most sophisticated model cannot model flow recirculation and ground vortices. It also lacks the possibility to model partial ground effect with a finite ground plane with multiple edges. Panel methods are much more flexible in this respect. For the transition between normal working state and windmill brake state, inflow models have been extended so that they do not show spurious behaviour in vortex ring state. The simplest versions however do not model the fluctuations in the inflow due to the turbulent nature of the vortex ring state. In summary, dynamic inflow models do have their use in flight simulation models, but without the use of multiple (empirical) extensions, they cannot be employed with much confidence in all possible flight conditions.
A review of rotorcraft wake modeling methods for flight dynamics applications
2009
27 Seiten, 22 Bilder, 160 Quellen
Aufsatz (Konferenz)
Datenträger
Englisch
A Review of Wake Modeling Methods for Flight Dynamics Applications
British Library Conference Proceedings | 2009
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