Abstract:

In many relevant flow cases, such as in jets or turbulent boundary layers, turbulent regions of the flow are bounded by non-turbulent fluid. The interface between such regions, the so-called turbulent/non- turbulent interface (TNTI) is known to remain sharp and well-defined even after long times. Here, we investigate how processes at the TNTI are related to turbulent entrainment, i.e. the incorporation of previously non-turbulent fluid into the turbulent flow. We show that turbulent entrainment is a viscous, small-scale process that is amplified by interface contortions across a range of scales. We also elucidate how these processes change in the presence of a stable stratification across the TNTI.

Brief Biograph:

Dominik graduated from TU Darmstadt (Germany) with a Master’s degree (Dipl. Ing.) in Mechanical engineering in 2010 and received his PhD from ETH Zurich (Switzerland) in 2014. He is a recipient of the McKenzie postdoctoral fellowship (2015-2018) of the University of Melbourne (Australia), where he worked as a post-doc in the group of Professor Ivan Marusic. In 2018, Dominik returned to Europe and joined the Physics of Fluids group at the University of Twente (Netherlands) as an Assistant Professor. His research interests include turbulent boundary layers, multiphase flows and experimental techniques such as Particle Tracking Velocimetry.