Modeling of wake features of a propeller using the vorticity confinement method

Abstract

The instability and evolution mechanisms of propeller wakes are of vital significance to the development of next-generation propulsion devices with better hydrodynamic and noise performances. The temporal–spatial scales and the vortex details are important for the understanding of the vortex features and their dynamic responses to the propeller. In the present study, the vorticity confinement (VC) method was employed on the numerical simulations achieved by the improved delay detached eddy simulation with various advance coefficients to characterize the underlying features of wake flows. Comparisons were made between the results computed with and without the VC model from different perspectives. The analyses showed that the VC method captures more high-frequency power spectral density results as well as more small-scale vortical topology on the far downstream field based on the same spatial resolution and indicates the multi-scale interference on the tip vortex evolutionary trajectories. The VC method also elucidates rich small vortical structures with low advance coefficient and elliptical instability with high advance coefficient. This paper further widens our knowledge on the propeller wake evolution mechanisms and highlights the value of the VC method in the investigation of propeller wakes.