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Full-Text Articles in Physics
Simple Model For Mixing At Accelerated Fluid Interfaces With Shear And Compression, John D. Ramshaw
Simple Model For Mixing At Accelerated Fluid Interfaces With Shear And Compression, John D. Ramshaw
Physics Faculty Publications and Presentations
A simple model was recently described for predicting linear and nonlinear mixing at an unstable planar interface between two fluids of different density subjected to an arbitrary time-dependent variable acceleration history [J. D. Ramshaw, Phys. Rev. E 58, 5834 (1998)]. Here we generalize this model to include the Kelvin-Helmholtz (KH) instability resulting from a tangential velocity discontinuity delta u, as well as the effects of a uniform anisotropic compression or expansion of the mixing layer as a whole. The model consists of a second-order nonlinear ordinary differential equation of motion for the half-width h of the mixing layer. This equation …
Effect Of Slow Compression On The Linear Stability Of An Accelerated Shear Layer, John D. Ramshaw
Effect Of Slow Compression On The Linear Stability Of An Accelerated Shear Layer, John D. Ramshaw
Physics Faculty Publications and Presentations
An analysis is given of the effect of a slow uniform anisotropic compression or expansion on the linear stability of a normally accelerated planar interface between two fluids with different densities and tangential velocities, i.e., a combined Kelvin-Helmholtz and Rayleigh-Taylor instability, but generalized to an arbitrary time-dependent acceleration history. The compression is presumed to be sufficiently slow that the density remains uniform within each fluid and hence depends only on time. The perturbation is taken to be sinusoidal with amplitude h(t). The time evolution of h is determined by requiring pressure continuity across the interface in the usual way. The …