Abstract
The method based on the continuous wavelet transformation to detect and characterize two-dimensional vortex is analyzed for a synthetic flow and applied to vortex detection of propeller wake. The characteristics of a vortex, such as center location, core radius, and circulation, are extracted based on the Lamb-Oseen and Rankine vortex models, the latter of which is a novel attempt. The effects of various factors such as the difference scheme, the grid and scale discretization, transform variable, and vortex model on vortex detection have been investigated thoroughly. The method is further applied to identify the tip vortex in a propeller wake.
Highlights
Vortical structures exist widely in nature and engineering applications, either harmful or beneficial
Detection was carried out using the Lamb-Oseen vortex model and enstrophy as the transform variable, and the derivatives were approximated by Richardson difference scheme (RDS) on a 101×101 grid
Detection was carried out using the enstrophy as transform variable and the derivatives were approximated by RDS on a 101 × 101 grid
Summary
Vortical structures exist widely in nature and engineering applications, either harmful or beneficial. Afterwards, the wavelet method has been widely used for detection of coherent structures in various turbulent flows [11,12,13,14,15,16]. Perret [24] proposed a new CWT based vortex detection method by using the swirling strength as the transform variable. We perform a comprehensive study of the detection method for a synthetic flow, to investigate the effects of difference scheme, grid and scale discretization, transform variable, and vortex model on Mathematical Problems in Engineering the detection results. This kind of analysis is still lacking in literature. The vortex is detected and the characteristics of the vortex are calculated through searching local maximum of the transformed results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
