Rayleigh-Taylor Instability of Newtonian and Oldroydian Viscoelastic Fluids in Porous Medium

1994 ◽  
Vol 49 (10) ◽  
pp. 927-930
Author(s):  
R. C. Sharma ◽  
V. K. Bhardwaj
Keyword(s):  
Porous Medium ◽  
Interfacial Tension ◽  
Viscoelastic Fluids ◽  
Taylor Instability ◽  
Horizontal Boundary ◽  
Wave Numbers ◽  
Unstable Configuration ◽  
Rayleigh Taylor Instability

AbstractThe Rayleigh-Taylor instability of viscous and viscoelastic (Oldroydian) fluids, separately, has been considered in porous medium. Two uniform fluids separated by a horizontal boundary and the case of exponentially varying density have been considered in both viscous and viscoelastic fluids. The effective interfacial tension succeeds in stabilizing perturbations of certain wave numbers (small wavelength perturbations) which were unstable in the absence of effective interfacial tension, for unstable configuration/stratification.

Rayleigh-Taylor Instability of a Partially Ionized Plasma in a Porous Medium in Presence of a Variable Magnetic Field

1992 ◽  
Vol 47 (12) ◽  
pp. 1227-1231
Author(s):  
R. C. Sharma ◽  
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Variable Magnetic Field ◽  
Taylor Instability ◽  
Wave Number ◽  
Medium Permeability ◽  
Wave Numbers ◽  
Rayleigh Taylor Instability ◽  
Partially Ionized ◽  
The Magnetic Field

Abstract The Rayleigh-Taylor instability of a partially ionized plasma in a porous medium is considered in the presence of a variable magnetic field perpendicular to gravity. The cases of two uniform partially ionized plasmas separated by a horizontal boundary and exponentially varying density, viscosity, magnetic field and neutral particle number density are considered. In each case, the magnetic field succeeds in stabilizing waves in a certain wave-number range which were unstable in the absence of the magnetic field, whereas the system is found to be stable for potentially stable configuration/stable stratifications. The growth rates both increase (for certain wave numbers) and decrease (for different wave numbers) with the increase in kinematic viscosity, medium permeability and collisional frequency. The medium permeability and collisions do not have any qualitative effect on the nature of stability or instability.

On the Stability of Two Superposed Viscous-Viscoelastic (Walters B′) Fluids

2006 ◽  
Vol 129 (1) ◽  
pp. 116-119 ◽  
Author(s):  
Pardeep Kumar ◽  
Roshan Lal
Keyword(s):  
Viscous Fluid ◽  
Viscoelastic Fluid ◽  
Kinematic Viscosity ◽  
Taylor Instability ◽  
Stable Configuration ◽  
Stabilizing Effect ◽  
Unstable Configuration ◽  
Rayleigh Taylor Instability ◽  
Newtonian Viscous Fluid ◽  
The Stability

The Rayleigh-Taylor instability of a Newtonian viscous fluid overlying Walters B′ viscoelastic fluid is considered. For the stable configuration, the system is found to be stable or unstable under certain conditions. However, the system is found to be unstable for the potentially unstable configuration. Further it is found numerically that kinematic viscosity has a destabilizing effect, whereas kinematic viscoelasticity has a stabilizing effect on the system.

scholarly journals Influence of ablation-to-critical surface distance upon Rayleigh–Taylor instability

1991 ◽  
Vol 9 (2) ◽  
pp. 273-281 ◽  
Author(s):  
J. Sanz ◽  
A. Estevez
Keyword(s):  
Growth Rate ◽  
Taylor Instability ◽  
Slab Thickness ◽  
Critical Surface ◽  
Slab Model ◽  
Surface Distance ◽  
Wave Numbers ◽  
Instability Growth ◽  
Rayleigh Taylor Instability ◽  
Ablation Front

The Rayleigh—Taylor instability is studied by means of a slab model and when slab thickness D is comparable to the ablation-to-critical surface distance. Under these conditions the perturbations originating at the ablation front reach the critical surface, and in order to determine the instability growth rate, we must impose boundary conditions at the corona. Stabilization occurs for perturbation wave numbers such that kD ˜ 10.

Density driven natural convection in a porous medium associated with Rayleigh-Taylor instability

2016 ◽  
Vol 2016 (0) ◽  
pp. I123
Author(s):  
Tetsuya Suekane ◽  
Yuji Nakanishi ◽  
Alexis Daniel Van Hoang Teston ◽  
Lei Wang
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Taylor Instability ◽  
Rayleigh Taylor Instability
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