The Unsteady Forces And Moments Induced By Blade-Vortex Interaction

The two-dimensional attached blade-vortex interaction problem is analyzed using two flow models: a theoretical model and a vortex flow model. In the theoretical study, a general viscous aerodynamic theory is applied to give a set of closed form formulas for the unsteady forces and moment induced by the blade-vortex interaction. These formulas are used to explain physical phenomena present in the blade-vortex interaction and to identify important parameters in unsteady load generation. The analytical formulas are also applied to the study of the noise generation mechanism of the blade-vortex interaction. The vortex flow model combines the theoretical analysis with a discrete vortex wake model. This new approach is extremely efficient and produces highly accurate results for attached blade-vortex interaction problems.