Dynamic stall induced by blade vortex interaction in helicopter descending flight
Dynamic stall induced by blade vortex interaction in helicopter descending flight
Date
2019
Authors
Gibertine, G.
Colli, A.
Zanotti, A.
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Abstract
In recent years studies have shown how blade-vortex interaction (BVI) can cause the onset of dynamic stall on helicopter rotors. In order to investigate this phenomenon wind tunnel tests were performed on a rotor model in descent flight conditions. The anaylsis of the rotor global performances indicated a defect of thrust for a particular value of collective pitch angle that can be explained as the occurrence of dynamic stall induced by a perpendicular vortex interaction. This conclusion is supported by evidence from both flapping angle measurements and by the results of numerical simulations performed using a code based on blade-element coupled with a vortex-particle wake model.