Transition to Turbulence in Wall-Bounded Shear Flows

Michael Karp
Work towards PhD degree under the supervision of Prof. Yaacov Cohen
Department of Aerospace Engineering
Technion – Israel Institute of Technology

Albeit great advancement, transition to turbulence continues to be an intriguing subject, challenging many researchers worldwide. The current research covers several aspects of transition – The evolution of coherent structures, such as counter-rotating vortex pairs and hairpins, observed in various transitional as well as turbulent flows is studied using a novel analytical-based numerical method for the evolution of localized disturbances in homogenous shear base-flows. A minimal element model capable of following the evolution of packets of hairpins is developed and compared successfully with experiments. Finally, an analytical model for transition via secondary instability of counter-rotating vortices in channel flow is presented. The model utilizes separation of scales between the slowly evolving base-flow and the rapidly evolving secondary disturbance to capture most transition stages using the multiple time scales method and its predictions are verified by comparison with direct numerical simulations.

The talk will be given in Hebrew

Wed, 15-06-2016, 16:30 (Gathering at 16:00)

Classroom 165, ground floor, Library, Aerospace Eng.

Light refreshments will be served before the lecture

Transition to Turbulence in Wall-Bounded Shear Flows