Finite-Amplitude Disturbances and Near-Threshold Instability of Hydrodynamic Flows
We consider theoretical models of possible initial stages of development, due to finite-amplitude wave instability,of turbulent spots in stratified shear flows when wave and flow parameters are near the stability threshold. It is shown that, in contrast to analogous processes in plasma, nonlinear frequency shift does not provide saturation of explosive resonant interaction of the marginal waves. A condition of instability due to redistribution of energy, by wave-induced turbulence, from the flow to wave is found and estimates of the growth rate are obtained analytically.
KeywordsInternal Wave Turbulent Spot Vertical Density Profile Free Surface Displacement Stratify Shear Flow
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- 1.Miropolsky, Yu.Z. Dynamics of internal gravity waves in the ocean. Moscow: Nauka 1981.Google Scholar
- 2.Barenblatt, G.I.: Some turbulent phenomena in a fluid with very stable stratification.In: Nonlinear waves.Stochasticity and turbulence. Gorky: Nauka 1980 89–14.Google Scholar
- 3.Moiseev, S.S.; Pungin, V.G.; Sagdeev, R.Z.; Suyazov, N.V.; Tur, A.V.; Yanovsky, V.V.: Secondary and correlational instabilities. In: Nonlinear waves. Self-organization.Moscow: Nauka 1983 85–95.Google Scholar
- 4.Moiseev, S.S.; Pungin, V.G.; Suyazov, N.V.; Etkin, V.S.;Explosive interactions of zero-energy waves in inviscid stratified shear flows. Izv. AN SSSR, FAO. 20 (1984) 9.Google Scholar
- 6.Davydova, T.A.: Explosive instability of zero energy waves and its stabilization in a plasma with a magnetized ion beam. Int. Conf. on Plasma Phys. Goteborg 1982 10p-11–24 192.Google Scholar
- 9.Moiseev, S.S.; Suyazov, N.V.; Etkin V.S.: Wave-turbulent instability of stratified shear flows. Preprint of Space Res. Inst. 905 (1984).Google Scholar
- 10.Pungin, V.G.; Suyazov, N.V.: Near-threshold instabilities in hydrodynamics. Proc. 2nd Int. Workshop on Nonl. and Turb. Processes in Phys. New York: Gordon and Breach 1984.Google Scholar