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
Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine