Numerical simulation of ice accretion on rotor airfoil of helicopter considering effects of centrifugal force

Considering the effects of centrifugal force, a method of numerical simulation for ice accretion on rotor airfoil of helicopter was established. Firstly, the body-fitted and body-orthogonal grids around an airfoil were generated and the viscosity flowfield around rotor airfoil was solved by Navier-Stokes (N-S) equations. Based on the solution of flowfield and Lagrange method, the equations of water droplets motion were established. Then, in order to improve the computational efficiency in searching the position of the water droplet, the method combined with the displacement vector was presented. Finally, in combination with the characteristics of blade motion, a three-dimensional ice accretion model considering the effects of the centrifugal force was presented. The comparison between the calculated results and experimental data indicates that the current approach can effectively simulate the ice accretion on airfoil of blade. Compared with the results of conventional ice accretion model, the amount of ice accretion was reduced by 22.3%. Considering the blade flapping motion, the amount of ice accretion was reduced more. As a result, the importance of the centrifugal force and blade motion in blade numerical simulation of ice accretion was pointed out. Comparing the ice shape and amount of the different sections of blade, the ice accretion characteristics of blade were discussed and analyzed. The results show that the effects of the centrifugal force increase with the increasing radial displacement, and the amount of ice accretion on the rotor lower surface decreases with the increase of the flapping angle.