There are many industrial situations where rods are used to stir a fluid, or where rods repeatedly stretch a material such as bread dough or taffy. The goal in these applications is to stretch either material lines (in a fluid) or the material itself (for dough or taffy) as rapidly as possible. The growth rate of material lines is conveniently given by the topological entropy of the rod motion....

We present experimental results of chaotic mixing of Newtonian fluids and yield-stress fluids using a rod-stirring protocol with a rotating vessel. We show how the mixing of yield-stress fluids by chaotic advection is reduced compared to the mixing of Newtonian fluids and explain our results, bringing to light the relevant mechanisms: the presence of fluid that only flows intermittently, a phen...

This article describes a soft pneumatic actuator that generates cyclical motion. The actuator consists of several (three, four, or five) chambers (arranged around the circumference of a circle surrounding a central rod) that can be actuated independently using negative pressure (or partial vacuum). Sequential actuation of the four-chamber device using reduced pressure moves the central rod cycl...

The present investigation compares the results of different fillers in terms physical, mechanical, and thermal characteristics epoxy polymers. These hybrid composites were produced using a mechanical stirring-assisted wet lay-up method with coir microparticles, fly ash, titanium carbide (TiC) nanoparticles, Innegra fabrics by stirring rod. tensile, flexural, interlaminar shear fabricated determ...

Abstract The friction between nanomaterials and Teflon magnetic stirring rods has recently drawn much attention for its role in dye degradation by dark. Presently the TiO 2 nanoparticles water been deliberately enhanced explored. As as 1.00 g were dispersed 50 mL 100 quartz glass reactor, which got gas-closed with about air a rod it. suspension reactor was magnetically stirred Flammable gases o...

In this study, we numerically investigate the evolution of two-dimensional mixing and heat transfer enhancement within a two-rod stirring device. The fluid is heated by the walls, which are maintained at a constant temperature. We show by analysis of different stirring protocols that the use of discontinuous wall rotations is necessary to promote heat transfer by chaotic mixing. This condition ...

An economical bioreactor designed for evaluating the biogas potential of particulate biomass is described. The bioreactor uses a simple stirring apparatus, called the Bordeaux stirrer, to enable gas-tight mixing of fermentation cultures. The apparatus consists of a low-rpm motor connected to a bent steel stir rod, which is placed in a length of flexible plastic tubing inserted through a rubber ...

We present a novel active mixing method in a microfluidic chip, where the controlled stirring of magnetic particles is used to achieve an effective mixing of fluids. To perform mixing, the ferromagnetic particles were embedded and manipulated under the influence of a rotating magnetic field. By aligning the magnetic beads along the magnetic field lines, rod-like structures are formed, functioni...