For more than 250 years, researchers have known that under certain conditions vapor bubbles can form in fluids moving swiftly over a surface. These bubbles soon collapse with such great force that they can poke holes in steel and damage objects such as ship propellers, turbine blades, nozzles and pump impellers.
Scientists have conducted extensive research for decades to try to understand this phenomenon -- called cavitation. But most experiments to date have been related to open-water objects like ship propellers.
Now a group led by Notre Dame professors Patrick Dunn and Flint Thomas has published the first detailed results of experiments aimed at preventing cavitation damage in jet fuel pumps, which are essential components in modern aircraft. Appearing in journal Physics of Fluids, which is published by the American Institute of Physics, the results showed great differences in cavitation behavior between water and JP-8 jet fuel, which is a complex mixture of more than 228 hydrocarbons and additives, each with its own fluid properties.
While it can be used to clean jewelry and disintegrate kidney stones, cavitation is usually considered to be highly detrimental and to be avoided. It was first described scientifically by Leonhard Euler in 1754, but the phenomenon made its initial impression with engineers in 1893 when it caused the failure of a propeller on the world’s fastest ship at the time, Great Britain’s HMS Daring. In modern times, degraded performance is the typical consequence, as maintenance crews usually discover and replace damaged components before they fail.
“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 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.”
The Notre Dame research provides jet-fuel pump designers with the first realistic data that they can use in their computer models to make better predictions of vulnerable locations in their pumps and systems where cavitation bubbles may be created and collapse.
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.
The article, "Experimental Characterization of Aviation-Fuel Cavitation" by Patrick F. Dunn, Flint O. Thomas, Michael P. Davis and Irina E. Dorofeeva appears in the journal Physics of Fluids. See: http://link.aip.org/link/phfle6/v22/i11/p117102/s1
Journalists may request a free PDF of this article by contacting email@example.com
This research was funded by Honeywell Corp.PHYSICS OF FLUIDS
Jason Socrates Bardi | Newswise Science News
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences