How do swimming microorganism interact with flow currents/structures? Using a flow cell, we show that Lagrangian vortex structures (following George Haller) enhance transport barriers by "expelling" swimmers. Check it out arxiv.org/abs/2312.14284 Beautifully done by Ranjiangshang Ran

How does particles settle in the presence of bacteria? In this new JFM article doi.org/10.1017/jfm.20…, we show that particle-bacteria interactions can lead to bioconvection patterns even in the dilute regime. With Shravan Pradeep, Doug Jerolmack, Bryan Maldonado, and Ranjiangshang Ran

Bacterial Barriers (Part 1): New manuscript with Ranjiangshang Ran in Journal of Fluid Mechanics shows how interactions between swimming bacteria and flow elliptic Lagrangian coherent structures George Haller form Lagrangian vortex boundaries (i.e., mixing barriers). See it at bit.ly/3RaXOWI

Hu et al. shows that successful dynamic large-eddy simulation models in turbulent flows hinges on the principal directions of the resolved strain rate tensor. By minimizing the Germano-identity error along fewer components, effective modeling is achieved! go.aps.org/3YdWiHI

Thanks to Journal of Fluid Mechanics & Jeff Guasto for highlighting our work on the interplay of bacterial activity and Lagrangian coherent structures in 2D flows - it leads to Bacterial Barriers | Journal of Fluid Mechanics | Cambridge Core - bit.ly/3y8tQwy with Ranjiangshang Ran

Our lab's very first paper is now on arXiv! This started as a "side project" when Haoyu Liu started his PhD! We learned a lot in the process and were finally able to explain how a colloidal vortex can form in low Re number flows due to solute gradients! arxiv.org/abs/2409.01594

Bacterial rheotaxis is ENHANCED in non-Newtonian fluids! In collaboration with Arnold Mathijssen, Albane Thery, and non-Xers. Read about our experiments and simulations in our new PNAS manuscript at pnas.org/doi/10.1073/pn… Mechanical Engineering and Applied Mechanics, Penn Penn Engineering APS Division of Fluid Dynamics APS DSOFT The Society of Rheology

Nice job Ranjiangshang Ran!

Our work on JFM is featured on GSNP image of the month.