High-Fidelity Numerical Ice Prediction on Rotors

This work presents an original framework to simulate the rotorcraft icing problem by utilizing state-of-the-art high-fidelity, three-dimensional numerical techniques. Furthermore, the inter-dependency between numerical techniques is highlighted as being a critical aspect of the framework. Techniques to address issues including mesh deformation, particle tracking, and phase change modelling are introduced. In particular, radial basis function mesh deformation techniques are used to update the three-dimensional moving ice boundary. Meanwhile, Lagrangian particle tracking techniques specific to rotorcraft flows are used to compute the collection efficiency of the rotor. Additionally, phase change models are applied to compute the ice thickness and a model to predict ice shedding events is introduced. Icing wind tunnel tests conducted on the Spinning Rotor Blade (SRB-II) model rotor are used for an assessment of the numerical predictions. Quantities used for comparisons between the numerical predictions and experimental measurements on the SRB-II model rotor include the ice thickness and shedding location. Numerical predictions are in good agreement with the measured data at all temperatures. Additionally, the outcome of influential parameters which directly impact rotor ice shapes are assessed. In particular, the model for the temperature profiles within the ice layer, and the centrifugally induced movement of the liquid film.