Helicopter flight around a ship's' superstructure

Abstract: A computationaluid dynamics model of a hovering helicopter main rotor is developed to examine airow in the presence of ship structures and side winds. An illustratio n of the problem is given. The rotor is modelled by modifying the governing N avier±Stokes equations in the region of the disc. The extra terms added to the governing equations apply a downward force to theuid; these forces are independent of theow around the rotor and are equal to the helicopter weight. The helicopter rotor model and the ship model are combined to yield oneow solution, which, due to the severe non-linearities of the problem, cannot be achieved by superpositio n. The resultantow yields valuable data about the induced velocities at the rotor, which ultima tely determine the control pitch and power required to maintain the hover in a given location. Indeed, the interactions between the rotor downwash and ship airow are known to produce unexpected and adverseight dynamic behaviour of the aircraft.