Convection of momentum transport events in a turbulent boundary layer

Momentum transport in turbulent boundary layers increases drag. Understanding how momentum transport events interact and evolve will allow us to find ways to control them. In this study, we determine the convection of momentum transport events from time-resolved particle image velocimetry measurements in a stream-wise wall-normal plane of a turbulent boundary layer at $Re_\tau\approx$ 2700. A field-of-view covering approximately $2\times0.5\delta$ with high spatial, $l^+=$ 20, and temporal resolution, $\Delta t^+=$ 0.7, allows us to determine convection velocities of momentum transport events of range of different sizes for wall-normal locations $y/\delta=$ 0.02 to 0.47 ($y^+=$ 60 to 1260). In the talk, a detailed description of convection of momentum transport events in different quadrants will be presented.