Verification of a LEWICE-based icing code with coupled heat transfer prediction and aerodynamics performance determination

A LEWICE-based ice accretion prediction code was developed by incorporating an empirical surface roughness and heat transfer modules suitable for glaze conditions with reduced horn growth. This study focused on verifying such proposed tool by comparing predictions to experimental results obtained at the NASA IRT. The work examines the accuracy of the prediction at different icing regimes over a wide range of testing conditions. A total of nine (9) icing conditions identified from literature and 14 icing conditions provided by an icing code validation campaign conducted at NASA Glenn Center were used for ice shape prediction comparison. The new heat transfer module combined with LEWICE predicted similar accuracy in the cold rime regime as the legacy heat transfer module used in LEWICE. It achieved better results in the glaze-rime transition regime, improving stagnation thickness prediction by an average of 73.3%, and partial improvement in the case of fishtail like shapes in fully glaze regimes, improving stagnation thickness prediction by 21.3%. The aerodynamics performance of iced airfoil was also predicted using empirical models proposed in prior work. Another 17 additional experimental measurements of rotor ice accretion were conducted. The performance degradation model was incorporated into a Blade Element Momentum Theory code for rotor torque prediction. The prediction was validated against both clean and iced rotor torque measurements. The prediction discrepancies were 9.8% and 15.6% respectively.