Numerical Simulations for Ice Accretion on Rotors Using New Three-Dimensional Icing Model

A new numerical method for predicting ice accretion on helicopter rotors is established. First, the orthogonal and body-fitted grids are generated around the rotor blade, and the computational fluid dynamics method for predicting flowfield of the rotor is established by solving the unsteady Reynolds-averaged Navier-Stokes equations. Based on the Eulerian approach, the conservation equations of mass and momentum are solved to obtain the droplet flowfield properties. Then, a new three-dimensional icing model considering the influences of the centrifugal force, the movement of water film, and the variation of the azimuthal angle is put forward. The comparisons between the calculated results and experimental data about the ice accretion on a rotor indicate that the present method is effective. At last, the effects of the atmospheric temperature and the advance ratio on the icing process are analyzed. At the subfreezing temperature, the ice amount near the stagnation point increases along the spanwise direction from blade root to blade tip. The total ice amount on a blade at each azimuthal angle varies sinusoidally in one rotation period in forward flight, and the variation amplitude increases with the increase of advance ratio.