Abstract: Dual-time step method and moving overset grid method are applied to simulate the multi-element airfoil. First, combined with preconditioning method, the flapping foil experiment of MIT (Massachusetts Institude of Technology) is simulated to validated the numerical method. A multi-element foil under the effect of gusts is simulated to give the disciplines of the aerodynamic forces changing with the phases of gusts. Simulated results shows that, the lower the frequency and the larger the amplitude of the gust, the larger the aerodynamic forces on the multi-element airfoils. On the other hand, the higher the frequency and the larger the amplitude of the gust, the more intense the gust will affect the aerodynamic forces on the multi-element airfoils.

Key words: dual-time step method, dynamic overset grid, gust wind, multi-element airfoil, preconditioning method