Visualization of Late-stage Transitional Structures in Numerical Data Using Vortex Identification and Feature Extraction

Vortices play a major role in many ows and an automated technique that reliably identies, tracks, and possibly isolates vortices o ers much promise for ow diagnostics. The presence of vortices in shear layers is one instance where identi cation using vorticity based identi cation is di cult. The present study has lead to the development of an enhanced feature identi cation and extraction algorithm based on the vortex de nition proposed by Jeong & Hussain [7] and on feature extraction similar to Silver [19]. The approach has been used in the case of a numerically simulated boundary layer undergoing laminar-turbulent transition. This type of ow eld has the advantage of o ering structures of increasing complexity in di erent streamwise regions useful for validation and veri cation of the approach.