Ice Accretion Model on Multi-Element Airfoil

Aircraft ice accretion is an important safety problem because of its degrading effects on aerodynamic performances. Simulation of this phenomenon using an icing wind tunnel is expensive, whereas numerical analyses offer several advantages in time and cost. The purpose of this paper is to simulate the ice shape on a multi-element airfoil. Icing accretion on a multi-element airfoil has already been analyzed in the past [Addy, Harold E., Jr., “Ice Accretions and IcingEffects forModernAirfoils,”NASATP-2000-210031.] [Tran, P., Brahimi,M.T., Tezok, F., and Paraschivoiu, I., Numerical Simulation of Ice Accretion on Multiple Element Configurations, ICAS Paper 96-2.7.5.]. Here different approaches are compared to identify the best in terms of a costs/benefits balance. Classical ice accretion models use a panel method to compute the aerodynamic field [Bragg, M. B., and Gregorek, G. M., “An Analytical Approach toAirfoil Icing,”AIAAPaper 81-0403, Jan. 1981.] [Gent, R.W., “Calculation ofWaterDroplet Trajectories About anAirfoil in Steady, Two-Dimensional, Compressible Flow,”RAETR-84060, Jun 1984.], but for high-lift configuration in the aerodynamic field there are large separation zones that are not simulated by panel codes, and that cannot be neglected. In this paper, ice accretion is calculated using several aerodynamics flow solvers [potential panel code, Euler, and Reynolds-averaged Navier-Stokes (RANS)] and several procedures for ice accretion simulation: single step, multistep time accretion strategy, and both single droplet and actual droplet spectrum for water impingement calculation.