Detection of burst‐events in the turbulent boundary layer

Abstract

The VITA (Variable‐Interval Time‐Averaging) technique is employed to detect burst‐events in the turbulent boundary layers for 10³ <Re_θ<10⁵, where Re_θ is the, Reynolds number based on the momentum thickness. The results show that the threshold level and integration time strongly affect the detected numbers of burst‐events and the conditionally averaged streamwise velocity fluctuation. The Reynolds number has little effect on the dimensionless mean frequency between bursts and the conditionally averaged streamwise velocity fluctuation distribution. The viscous time scale is conjectured to be the appropriate variable for scaling the mean period between bursts in the wall region.

Key words:

• burst
• turbulent boundary layer
• VITA