Tamer Zaki, PhD, Associate Professor, Mechanical Engineering, Johns Hopkins University
The Elusive Onset of Turbulence And The Laminar-Turbulence Interface: The onset of chaotic fluid motion from an initially laminar, organized state is an intriguing phenomenon referred to as laminar-to-turbulence transition. Early stages involve the amplification of seemingly innocuous small-amplitude perturbations. Once these disturbances reach appreciable amplitudes, they become host to sporadic bursts of turbulence — a chaotic state whose complexity is only tractable by high-fidelity large-scale simulations. By performing direct numerical simulations that resolve the dynamics of laminar-to-turbulence transition in space and time, and storing the full history of the flow evolution, we capture the rare high-amplitude events that give way to turbulence and unravel key characteristics of the laminar-turbulence interface.