01. Experimental/Computational Fluid Dynamics

When generating flows for specific fluids such as highly pure liquids or radioactively contaminated water, one should prevent the working fluid from being in direct contact with the fluid machine. For example, in infusion pumps, which are a type of medical device, finger- and roller-type pumps are widely used. In both pump types, the fluid is supplied via the shape changes of the tube over time by the pump drive unit. Additionally, the pumping method for both is based on temporal changes in the tubing shape at the pump drive. As the chemical solution is not in direct contact with the fluid machinery, contamination by bacteria and other contaminants can be prevented. Synthetic jets generate flow using an oscillating body without requiring a rotating machine. In fact, synthetic jets use the vibration of an elastic body to generate an actual downstream flow owing to entrainment, even though the net flow rate is zero at the outlet. Therefore, in principle, synthetic jets can generate flow in a closed liquid container while maintaining airtightness. However, information regarding the jet structure in a closed liquid container is limited, and reports regarding synthetic jets in liquids are scarce. In this study, the behavior of synthetic jets in a two-dimensional rectangular tank is observed to investigate flow generation in a closed container. The effect of dimensionless strokes on the flow characteristics of synthetic jets in a vessel is investigated. The main results show a circulating flow in the vessel for various non-dimensional strokes and the possibility of sloshing at the free surface when the fundamental frequency of the synthetic jet is similar to the natural frequency of the liquid surface.

Prof.

Donghyuk Kang