Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

PDF

Mechanical Engineering

Selected Works

2012

Xiaoning Shen

Articles 1 - 2 of 2

Full-Text Articles in Entire DC Network

Undulatory Swimming In Viscoelastic Fluids, Xiaoning Shen, Paulo E. Arratia Nov 2012

Undulatory Swimming In Viscoelastic Fluids, Xiaoning Shen, Paulo E. Arratia

Xiaoning Shen

The effects of fluid elasticity on the swimming behavior of the nematode Caenorhabditis elegans are experimentally investigated by tracking the nematode’s motion and measuring the corresponding velocity fields. We find that fluid elasticity hinders self-propulsion. Compared to Newtonian solutions, fluid elasticity leads to up to 35% slower propulsion. Furthermore, self-propulsion decreases as elastic stresses grow in magnitude in the fluid. This decrease in self-propulsion in viscoelastic fluids is related to the stretching of flexible molecules near hyperbolic points in the flow.


Propulsive Force Measurements And Flow Behavior Of Undulatory Swimmers At Low Reynolds Number, Josué Sznitman, Xiaoning Shen, Raphael Sznitman, Paulo E. Arratia Nov 2012

Propulsive Force Measurements And Flow Behavior Of Undulatory Swimmers At Low Reynolds Number, Josué Sznitman, Xiaoning Shen, Raphael Sznitman, Paulo E. Arratia

Xiaoning Shen

The swimming behavior of the nematode Caenorhabditis elegans is investigated in aqueous solutions of increasing viscosity. Detailed flow dynamics associated with the nematode’s swimming motion as well as propulsive force and power are obtained using particle tracking and velocimetry methods. We find that C. elegans delivers propulsive thrusts on the order of a few nanonewtons. Such findings are supported by values obtained using resistive force theory; the ratio of normal to tangential drag coefficients is estimated to be approximately 1.4. Over the range of solutions investigated here, the flow properties remain largely independent of viscosity. Velocity magnitudes of the flow …