Poster: Visualizing Hydrodynamic Interaction of Scaled-up Flagella Model

The physical swimming mechanisms used by microorganisms like bacteria are different compared to larger animals like humans. Escherichia Coli (E. Coli) bacteria use hair-like structures called flagella for locomotion. During translational movement, the flagella intertwine to create a bundle, the physical basis of which is not fully understood. To understand flagellar bundling, we created a macro model of four active flagella and one passive flagellum in silicon oil. We are testing if the four active flagella rotating together can give rise to sufficient drag in the surrounding fluid which is capable of propelling the passive one. The Reynolds number is kept constant with actual bacteria (~10^-2). We use Particle image velocimetry (PIV), using tracer particles and laser sheet. I will discuss the experimental design and computational implementation of PIV and then show results obtained in terms of the mean flow field and vorticity for a single model flagellum and how we can extrapolate that learning to our actual five flagella setup.