The technique allowed the engineers to negotiate the dramatic size differences between the strands and original liquid, a process that falls in the realm of "multi-scale modeling."
"Our approach allowed us to do this multi-scale modeling in one big calculation," Basaran said.
In the experiments, an electric voltage was applied to a small metal rod positioned about an inch from a puddle of liquid. The liquid was pulled toward the tip of the rod and took on a conical appearance. Strands of liquid, which subsequently broke into droplets, were then emitted from the liquid cone.
The Purdue researchers conducted experiments using liquids with large viscosities, including those similar to fuels, whereas past research has concentrated on lower viscosity fluids like water.
"This may prove to be important in combustion applications because fuel is sprayed into engine cylinders using fuel injectors," Basaran said. "We studied higher viscosity fluids to see the effect of viscosity, which other people had never seen before. It turns out that the viscosity actually has a big effect on droplet size."
Future research will continue to study how droplet formation is influenced by other characteristics of a liquid. These characteristics include the electrical conductivity of fluids and the surface tension, the latter being responsible for the beading of water droplets on a recently waxed car.
"We are just scratching the surface because there is such a large range of viscosities and other characteristics of fluids that affect droplet formation and size," Basaran said. "There could be many surprises."
|Contact: Emil Venere|