| Abstract: | Conclusions In the transitional stage of the evolution of small perturbations in a flowing stratified fluid various structures may be formed. The form of these structures will depend on the initial conditions, the velocity shear, the stratification, and the dissipative characteristics of the fluid. In some cases in the intermediate stage the perturbations may increase.However, at large times in the final dissipative stage all the perturbations decay and the structure of the longest-lived of them is fairly simple. Owing to the shear effect the surviving perturbations are highly elongated in the direction of flow. However, under the influence of the stratification, from all the perturbations with  h L/g in the transverse plane perturbations of two types are gradually filtered out: internal waves and thin horizontal layered structures.In the presence of shear flow the layered structure in a stratified fluid is not only preserved but even becomes more sharply expressed owing to the suppression by the shear if many of the competing perturbations.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 94–102, March–April, 1988. |
