Applied Math Colloquium | Sarah Olson, Fluid Flows with Immersed Structures: from micro-swimmers to rigid obstacles

Thursday, October 10, 2024 2:30 pm - 3:30 pm EDT (GMT -04:00)

MC 5501

Speaker

Sarah Olson, Worcester Polytechnic Institute

Title

Fluid Flows with Immersed Structures: from micro-swimmers to rigid obstacles

Abstract

We will discuss two very different problems in fluid dynamics where we would like to advance our understanding of the coupling of a structure immersed in a viscous fluid.  The fluid flow will be altered due to the presence of the structure by a combination of forces exerted on the structure by the flow and potential forces a structure exerts on the fluid. In the first part, we will look at a micro-swimmer model where given noisy data for the swimming trajectory, a Bayesian approach is utilized to estimate fluid and/or material parameters. We can estimate correlations between model parameters and gain insight on emergent swimming trajectories of actuated elastic filaments. In the second part, we will look at a shape optimization problem. We try to answer the question of whether the placement of a rigid obstacle in a flow could create a pre-specified Lagrangian Coherent Structure past the obstacle. Utilizing techniques from abstract shape optimization, we show that such optimal obstacles exist, and we outline a framework to identify these obstacles.