Oscillatory extensional flow based on eccentric cylinder flow

At present, researching the dynamics of dispersed phases generally uses simple shear flows, simple extensional flows, and oscillatory shear flows rather than an oscillatory extensional flow because it is more difficult to experimentally implement. In this research, a method to generate the oscillatory extensional flow using an eccentric cylinder flow was proposed. Although the eccentric cylinder flow is a shear-extensional complex flow, the shear flow in specific regions of the flow field is very weak when the inner and outer cylinders co-rotate at a particular angular velocity ratio, and only the extensional flow remains. Therefore, the oscillatory extensional flow can be generated in this region when cylinders oscillate at this angular velocity ratio. Larger eccentric and radius ratios are suitable to generate an oscillatory extensional flow with high frequency, and the amplitude can be controlled by the angular velocity of cylinders. This flow field is promising to be a rheological tool for investigating the effects of extensional flows on dispersion dynamics.

Automated summary

The method proposed in the research generates oscillatory extensional flow using an eccentric cylinder flow, with the frequency and amplitude controlled by the angular velocity and eccentricity of the cylinders. This flow field shows promise as a rheological tool for investigating the effects of extensional flows on dispersion dynamics.