Richtmyer–Meshkov instability
The Richtmyer–Meshkov instability (RMI) occurs when two fluids of different density are impulsively accelerated. Normally this is by the passage of a shock wave. The development of the instability 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. This instability can be considered the impulsive-acceleration limit of the Rayleigh–Taylor instability[citation needed].
History
R. D. Richtmyer provided a theoretical prediction,[1] and E. E. Meshkov (Евгений Евграфович Мешков)(ru) provided experimental verification.[2] Materials in the cores of stars, like Cobalt-56 from Supernova 1987A were observed earlier than expected. This was evidence of mixing due to Richtmyer–Meshkov and Rayleigh–Taylor instabilities[citation needed].
Examples
During the implosion of an inertial confinement fusion target, the hot shell material surrounding the cold D-T fuel layer is shock-accelerated. This instability is also seen in Magnetized target fusion.[3] 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.
Supersonic combustion in a Scramjet may benefit from RMI as the fuel-oxidants interface is enhanced by the breakup of the fuel into finer droplets. Also in studies of deflagration to detonation transition (DDT) processes show that RMI-induced flame acceleration can result in detonation.
See also
- Rayleigh–Taylor instability
- Mushroom cloud
- Plateau–Rayleigh instability
- Salt fingering
- Kármán vortex street
- Kelvin–Helmholtz instability
- Hydrodynamics
References
- ^ Richtmyer, Robert D. (1960). "Taylor Instability in a Shock Acceleration of Compressible Fluids". Communications on Pure and Applied Mathematics. 13 (2): 297–319. doi:10.1002/cpa.3160130207.
- ^ Meshkov, E. E (1969). "Instability of the Interface of Two Gases Accelerated by a Shock Wave". Soviet Fluid Dynamics. 4 (5): 101–104. Bibcode:1972FlDy....4..101M. doi:10.1007/BF01015969. S2CID 123494913.
- ^ "On the collapse of a Gas Cavity by an Imploding Molten Lead Shell and Richtmyer-Meshkov Instability" Victoria Suponitsky, et al. General Fusion Inc, 2013
- Mikaelian, Karnig O. (1985-01-01). "Richtmyer-Meshkov instabilities in stratified fluids". Physical Review A. 31 (1). American Physical Society (APS): 410–419. doi:10.1103/physreva.31.410. ISSN 0556-2791. PMID 9895490.
External links
- Wisconsin Shock Tube Laboratory
- New type of interface evolution in the Richtmyer–Meshkov instability
- Recent Advances in Indirect Drive ICF Target Physics at LLNL
- Emergence of Detonation in the Flowfield Induced by Richtmyer–Meshkov Instability
- Propagation of Fast Deflagrations and Marginal Detonations in Hydrogen-Air Mixtures
- Mushrooms+Snakes: a visualization of Richtmyer–Meshkov instability
- Conjugate Filter OscillationReduction (CFOR) scheme for the 2D Richtmyer–Meshkov instability
- Experiments on the Richtmyer–Meshkov instability at the University of Arizona[dead link]