Richtmyer-Meshkov instability
Encyclopedia
Shock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...
. The development of the instability
Instability
In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds...
begins with small amplitude perturbations which initially grow linearly with time. This is followed by a nonlinear regime with bubbles appearing in the case of a light fluid penetrating a heavy fluid, and with spikes appearing in the case of a heavy fluid penetrating a light fluid. A chaotic regime eventually is reached and the two fluids mix.
During the implosion of an inertial confinement fusion
Inertial confinement fusion
Inertial confinement fusion is a process where nuclear fusion reactions are initiated by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium....
target, the hot shell material surrounding the cold D
Deuterium
Deuterium, also called heavy hydrogen, is one of two stable isotopes of hydrogen. It has a natural abundance in Earth's oceans of about one atom in of hydrogen . Deuterium accounts for approximately 0.0156% of all naturally occurring hydrogen in Earth's oceans, while the most common isotope ...
-T
Tritium
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...
fuel layer is shock-accelerated. Mixing of the shell material and fuel is not desired and efforts are made to minimize any tiny imperfections or irregularities which will be magnified by RMI.
At an entirely different scale, stellar core materials (e.g. Cobalt-56) from Supernova 1987A
SN 1987A
SN 1987A was a supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, a nearby dwarf galaxy. It occurred approximately 51.4 kiloparsecs from Earth, approximately 168,000 light-years, close enough that it was visible to the naked eye. It could be seen from the Southern...
were observed earlier than expected, giving evidence of turbulent mixing due to Richtmyer–Meshkov and Rayleigh–Taylor instabilities.
Between these two extremes, supersonic combustion in a Scramjet
Scramjet
A scramjet is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow...
may benefit from RMI as the fuel-oxidants interface is enhanced by the breakup of the fuel into finer droplets.
The study of deflagration to detonation transition
Deflagration to detonation transition
Deflagration to detonation transition refers to a phenomenon in ignitable mixtures of a flammable gas and air when a sudden transition takes place from a deflagration type of combustion to a detonation type of combustion...
(DDT) processes show that RMI-induced spontaneous flame acceleration can result in detonation.
RMI can be considered the impulsive-acceleration limit of the Rayleigh–Taylor instability.
R. D. Richtmyer
Robert D. Richtmyer
Robert Davis Richtmyer was an American physicist, mathematician, educator, author, and musician.-Biography:Richtmyer was born on October 10, 1910 in Ithaca, New York.His father was physicist Floyd K...
provided a theoretical prediction in "Taylor instability in a shock acceleration of compressible fluids", Communications on Pure and Applied Mathematics
Communications on Pure and Applied Mathematics
Communications on Pure and Applied Mathematics is a scientific journal which is associated with the Courant Institute of Mathematical Sciences. It publishes original research originating from or solicited by the institute, typically in the fields of applied mathematics, mathematical analysis, or...
13, 297-319 (1960).
E. E. Meshkov (Евгений Евграфович Мешков) provided experimental verification in "Instability of the Interface of Two Gases Accelerated by a Shock Wave", Soviet Fluid Dynamics 4,101-104 (1969).
See also
- Rayleigh–Taylor instability
- Mushroom cloudMushroom cloudA mushroom cloud is a distinctive pyrocumulus mushroom-shaped cloud of condensed water vapor or debris resulting from a very large explosion. They are most commonly associated with nuclear explosions, but any sufficiently large blast will produce the same sort of effect. They can be caused by...
- Plateau–Rayleigh instability
- Salt fingeringSalt fingeringSalt fingering is a mixing process that occurs when relatively warm, salty water overlies relatively colder, fresher water. It is driven by the fact that heated water diffuses more readily than salty water...
- Kármán vortex street
- Kelvin–Helmholtz instability
- Hydrodynamics