An Efficient POD Based Technique to Model Rotor/Ship Airwake Interaction

Ship airwake data generated using CFD cannot be directly used in real time simulation of helicopter shipboard operations because of the computational overhead. To address this issue, a POD based technique has been developed to model rotor/ship airwake interaction in a computationally efficient manner while maintaining simulation fidelity. The data derived using POD is shown to capture both the spatial and temporal variations of CFD airwake computations accurately. This technique is used in a methodology developed to facilitate two-way coupling between the rotor wake and ship airwake. The coupling results for a helicopter hovering above the ship deck show that airwake coupled with rotor wake exhibits significantly different flow characteristics compared to the isolated ship. The coupled airwake is seen to induce higher vibratory loads on the helicopter although the effect is dependent on position of the helicopter w.r.t the ship.