Abstract
The present paper is concerned with the behavior of single streamwise vortex embedded in Blasius boundary layer. Our main aim is to study the subcritical transition caused by single streamwise vortex. It is interesting to see how the vortex can trigger a sequence of events leading to the transition. In the present study we observed the flow at the momentum thickness Reynolds number Rθ=160 to 180. We found that a streamwise vortex with Γ/v= 72 can disturb the Blasius flow such that the local flow surrounding the vortex core exhibits inflectional instabilities and amplifies small disturbances. It should be emphasized that the inflectional instabilities undergo synchronizing with the instability of the vortex core itself.
