MAE/PICSciE seminar: Stability Analysis of an Impacting T-Junction Pipe Flow - 12/9 at noon - EQuad J223
Mechanical and Aerospace Engineering
Monday, December 9, 2013
12:00 – 1:00 pm, EQuad J223
Pizza will be provided.
The fluid flow through a T-shaped pipe bifurcation (with the inlet at the bottom of the "T") is a very familiar occurrence in both natural and man-made systems. Everyday examples include industrial pipe networks, microfluidic channels, and blood flows in the heart and brain. Despite the ubiquitous nature of the geometry, many questions about the flow physics remain, and prior analyses have been rudimentary and qualitative. This seminar addresses three important questions: 1) How does the flow evolve with Reynolds number? 2) What are the important flow structures? 3) Lastly, where does the flow exhibit dynamical sensitivity? Much of this research focuses on the relation between recirculation regions in the outlet pipes and the regions of stability, receptivity, and sensitivity as defined by linear stability theory. The recirculation regions, which exist above a Reynolds number of 320, exhibit a characteristic vortex breakdown phenomenon. At a Reynolds number of 556, a rapid sequence of supercritical Hopf bifurcations begins. In this geometry, regions of growth are concentrated in the outlet pipes, but regions of receptivity to initial conditions and disturbances are confined to the front and back walls of the inlet and junction. Finally, the flow is most sensitive to localized dynamical perturbations in the recirculation regions. The recirculation can cause small perturbations to feed back on themselves, leading to large changes in dynamics.
Audience: Grad Students and researchers
Location: EQuad J223
Date/Time: 12/09/13 at 12:00 pm - 12/09/13 at 1:00 pm