Numerical Simulations of the Pitching Airfoil by Using Discrete Vortex Method

This paper presents a two-dimensional discrete vortex method that uses the vortex growing core model to simulate the unsteady force and the wake patterns of the pure pitching airfoil efficiently and accurately. To avoid the random fluctuation caused by the random walk method, a vortex growing core method is used to simulate the viscous diffusion motion. In addition, the vortices fall off randomly on the body surface. Referring to the experimental configurations of Mackowski and Williamson (2015), a good agreement is achieved through the comparisons between the present simulation results and the experimental results, including the mean force coefficients, oscillation amplitude and wake patterns. It shows that the two-dimensional discrete vortex method can be used to predict the mechanical behavior and wake patterns on the pitching airfoil motion.