Abl Inclusion Effects On Rotor Airloads Simulations In A Shipborne Environment

Abstract

This paper gathers the experience gained in exploring the possible setups for a new computational methodology to evaluate the aerodynamic field on ship decks. With respect to the legacy approach used in Leonardo Helicopters Division, the new workflow tries to erode the conservativism limits assumed on the results by improving the accuracy of the outcomes when estimating transient airloads on helicopter blades during start-up procedures on ship decks. All steps of have been developed to be automatable for industrial applications. The improvement in aerodynamics with respect to the previous study takes into account the Atmospheric Boundary Layer (ABL) in an efficient manner, and compare it with other possible numerical models described in literature. The impact on the blade loads derivating from the ABL is be presented through its effect on the rotor loads during start-up manoeuvres. Taking into account the ABL becomes relevant only as the ship orientation changes towards 90°, and affects the rotor airloads depending on the sea state, on the hull height and on the rotor placement on deck.