New research examines cavitation inside jet fuel pumpsNovember 18, 2010
A group of Notre Dame professors has published the first detailed results of experiments aimed at preventing cavitation damage in jet fuel pumps. The research is featured in the latest issue of the journal of Physics and Fluids, published by the American Institute of Physics.
Cavitation is caused by vapor bubbles forming in fluids that are moving quickly over a surface. The bubbles can collapse with such force that they poke holes in steel and cause damage to ship propellers, turbine blades, nozzles and pump impellers. Scientists have tried for years to understand -- and find ways to prevent -- cavitation, but most of the experiments have been related to open-water objects such as ship propellers.
The research of Notre Dame professors Patrick Dunn and Flint Thomas provides jet-fuel pump designers with the first realistic data that they can use in their computer models to make better predictions about vulnerable locations in their pumps and systems -- places where cavitation bubbles may form and then collapse, according to a American Institute of Physics news release.
"Improved jet-fuel pumps are needed particularly for military aircraft being designed to fly at higher altitudes and in other demanding environments," Dunn said. "But pump manufacturers still rely heavily upon trial-and-error in design. If they were confident that a computer-designed pump would work as predicted, new pumps could be lighter, more efficient and have longer lifetimes."
It's much more difficult to model cavitation in pumps than in open water, Dunn added, because the fluid typically has a turbulent journey with accelerated flows though small channels, orifices, and spinning discs. With so many constituents, jet fuel is also a computer modeler's nightmare. Its properties can even change with storage conditions and is often contaminated with microparticles that can promote cavitation.