Douglas Harper's Etymology Dictionary
"formation of bubbles in fluid," 1895, from cavity + -ation. Earlier as a medical term (1868).
Wiktionary
n. 1 The formation of pits on a surface. 2 (context science English) The formation, in a fluid, of vapor bubbles that rapidly collapse; especially in a rotating marine propeller or pump impeller. 3 (context biology English) The formation of cavities in an organ, especially in lung tissue as a result of tuberculosis.
Wikipedia
Cavitation is the formation of vapour cavities in a liquid – i.e. small liquid-free zones ("bubbles" or "voids") – that are the consequence of forces acting upon the liquid. It usually occurs when a liquid is subjected to rapid changes of pressure that cause the formation of cavities where the pressure is relatively low. When subjected to higher pressure, the voids implode and can generate an intense shock wave.
Cavitation is a significant cause of wear in some engineering contexts. Collapsing voids that implode near to a metal surface cause cyclic stress through repeated implosion. This results in surface fatigue of the metal causing a type of wear also called "cavitation". The most common examples of this kind of wear are to pump impellers, and bends where a sudden change in the direction of liquid occurs. Cavitation is usually divided into two classes of behavior: inertial (or transient) cavitation and non-inertial cavitation.
Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a shock wave. Inertial cavitation occurs in nature in the strikes of mantis shrimps and pistol shrimps, as well as in the vascular tissues of plants. In man-made objects, it can occur in control valves, pumps, propellers and impellers.
Non-inertial cavitation is the process in which a bubble in a fluid is forced to oscillate in size or shape due to some form of energy input, such as an acoustic field. Such cavitation is often employed in ultrasonic cleaning baths and can also be observed in pumps, propellers, etc.
Since the shock waves formed by collapse of the voids are strong enough to cause significant damage to moving parts, cavitation is usually an undesirable phenomenon. It is very often specifically avoided in the design of machines such as turbines or propellers, and eliminating cavitation is a major field in the study of fluid dynamics. However, it is sometimes useful and does not cause damage when the bubbles collapse away from machinery, such as in supercavitation.
Cavitations are an area of dead bone caused by a dearth of blood flow to that part of the bone. A cavitation is a hole in the blood vessel that cannot be visually detected with the naked eye. Jawbone cavitations, also called neuralgia-inducing cavitational osteonecrosis (NICO) if they are associated with pain, are extraction sites in the jaw that have not healed.
Cavitation may refer to:
- Cavitation in physics, the formation of vapour bubbles in a liquid
- Cavitation (biology), the formation of cavities in an organ
- Cavitation (elastomers), the unstable expansion of a microscopic void in a solid elastomer under the action of tensile hydrostatic stresses
Cavitation, in biology, is the formation of cavities in an organ, especially in lung tissue as a result of tuberculosis. It can also be caused by squamous cell lung carcinoma after necrosis of the central part.
Cavitation is the unstable unhindered expansion of a microscopic void in a solid elastomer under the action of tensile hydrostatic stresses. This can occur whenever the hydrostatic tension exceeds 5/6 of Young's modulus.
The cavitation phenomenon may manifest in any of the following situations:
- imposed hydrostatic tensile stress acting on a pre-existing void
- void pressurization due to gases that are generated due to chemical action (as in volatilization of low-molecular weight waxes or oils: 'blowpoint' for insufficiently cured rubber, or 'thermal blowout' for systems operating at very high temperature)
- void pressurization due to gases that come out of solution (as in gases dissolved at high pressure)
Usage examples of "cavitation".
The cavitation of the Moon was to be induced by eighteen missiles that would travel from a distant circle toward its equatorial surface along trajectories of the involute type.
As a result, the planned concentration of blows in the lunar core did not come about, and the cavitation took place eccentrically.
In the eighth second of the cavitation, billowing shock waves, aflame, gave the rent Moon the appearance of a burning bush in space.
As it completed its first circle, the passive receptors in the nose heard the cavitation noises of the submarine and homed in on them.
Suddenly they heard the sound of propeller cavitation as the submarine went to full power and turned.
The torpedo was running deep to take advantage of the water pressure that reduced cavitation noise, hence reducing the range at which the Alfa could detect it.
The Heechee ships had flashed about the floating arcologies of the people with much cavitation and significant local temperature rises.
He had already caused several troublesome cavitation pockets, and the whole slurpy environment they lived in was troubled.
In the eighth second of the cavitation, billowing shock waves, aflame, gave the rent Moon the appearance of a burning bush in space.
Depending on how much damage it did as it degraded, we could have cavitation in the main chambers.
The Line Inspectors, who know their stuff, say that those cavitations are objectionable.
They use a semiplaning monohull with water jets that eliminate propeller cavitation.
The seven-bladed propeller enabled almost twenty knots without a hint of noisy cavitation, and the reactor plant operated in almost all regimes on natural convection circulation, obviating the need for potentially noisy feed-pumps.