A Comparison Of Low- And High-Fidelity Models For Tail Rotor Icing Phenomena

Abstract

A low-fidelity model for modeling ice accretion phenomena over two-bladed teetering rotors has been developed. In this approach, the blades are assumed to be rigid, and the flapping motion is caused by the inertial, centrifugal, and aerodynamic forces acting on the blade section. The aerodynamic forces are computed using a table look-up of precomputed airfoil lift and drag coefficients as a function of effective angle of attack. Following the analysis of the rotor without icing effects, ice shapes at selected radial locations on the rotor are computed. The impact of ice shapes on the 2-D lift and drag characteristics is estimated using a 2-D CFD analysis. Finally, the rotor is reanalyzed using the low fidelity model with the iced airfoil lift and drag characteristics. Calculations have been done for the dry rotor, and two specific icing test conditions. Comparisons with test data and a higher fidelity model are presented.