Experimental Rayleigh-Taylor Instability in a Circular Tube

1985 ◽  
Vol 107 (4) ◽  
pp. 460-466 ◽  
Author(s):  
J. W. Jacobs ◽  
A. Bunster ◽  
I. Catton ◽  
M. S. Plesset
Keyword(s):  
Linear Theory ◽  
Circular Tube ◽  
Water System ◽  
Taylor Instability ◽  
Pressure Differential ◽  
Gravitational Acceleration ◽  
Inside Diameter ◽  
Wave Numbers ◽  
Rayleigh Taylor Instability

The Rayleigh-Taylor instability of an air-water system has been investigated experimentally. The instability was produced by accelerating a slug of water down a vertical circular tube of 6.25 in. inside diameter employing a pressure differential. Accelerations from 3 to 25 times gravitational acceleration with fluid depths from 5 to 20 centimeters were studied. The disturbances first observed were purely axisymmetric with wave numbers corresponding closely to the fastest growing values given by linear theory. Later stages of planform development were characterized by a series of transitions which cannot be predicted by linear theory. These transitions were correlated with disturbance height.

Three-dimensional Rayleigh-Taylor instability Part 2. Experiment

1988 ◽  
Vol 187 ◽  
pp. 353-371 ◽  
Author(s):  
J. W. Jacobs ◽  
I. Catton
Keyword(s):  
High Speed ◽  
Small Volume ◽  
Circular Tube ◽  
Three Dimensional ◽  
Vertical Tube ◽  
Taylor Instability ◽  
Gravitational Acceleration ◽  
Lateral Direction ◽  
Weakly Nonlinear ◽  
Rayleigh Taylor Instability

Three-dimensional Rayleigh-Taylor instability, induced by accelerating a small volume of water down a vertical tube using air pressure, is investigated. Two geometries are studied: a 15.875 cm circular tube and a 12.7 cm square tube. Runs were made with initial disturbances in the form of standing waves forced by shaking the test section in a lateral direction. Accelerations ranging from 5 to 10 times gravitational acceleration and wavenumbers from 1 cm−1 to 8 cm−1 are studied. The resulting instability was recorded and later analysed using high-speed motion picture photography. Measurements of the growth rate are found to agree well with linear theory. In addition, good qualitative agreement between photographs and three-dimensional surface plots of the weakly nonlinear solution of Part 1 of this series (Jacobs & Catton 1988) is obtained.

Nonlinear Rayleigh–Taylor instability in hydromagnetics

1976 ◽  
Vol 15 (2) ◽  
pp. 239-244 ◽  
Author(s):  
G. L. Kalra ◽  
S. N. Kathuria
Keyword(s):  
Magnetic Field ◽  
Power Generation ◽  
Growth Rate ◽  
Linear Theory ◽  
Nonlinear Theory ◽  
Taylor Instability ◽  
Rayleigh Taylor Instability ◽  
Image Position

Nonlinear theory of Rayleigh—Taylor instability in plasma supported by a vacuum magnetic field shows that the growth rate of the mode, unstable in the linear theory, increases if the wavelength of perturbation π lies betweenand 2πcrit. This might have an important bearing on the proposed thermonuclear MHD power generation experiments.

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.

Rayleigh–Taylor instability of a plasma in a magnetic field: nonlinear theory

1982 ◽  
Vol 27 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Bhimsen K. Shivamoggi
Keyword(s):  
Magnetic Field ◽  
Nonlinear Analysis ◽  
Linear Theory ◽  
Nonlinear Theory ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Taylor Instability ◽  
Rayleigh Taylor Instability ◽  
Linear Cut

Kaira & Kathuria used the method of multiple scales to develop nonlinear analysis of Rayleigh–Taylor instability of a plasma in a magnetic field. Their calculations remain valid only for wavenumbers k away from the linear cut-off value kc, and break down for wavenumbers near kc. The purpose of this paper is to treat the latter case. The solution uses the method of strained parameters. The results show the instability persists even at k = kc, despite the cut-off predicted by the linear theory.

Multiple cutoff wave numbers of the ablative Rayleigh-Taylor instability

1994 ◽  
Vol 50 (5) ◽  
pp. 3968-3972 ◽  
Author(s):  
R. Betti ◽  
V. Goncharov ◽  
R. L. McCrory ◽  
E. Turano ◽  
C. P. Verdon
Keyword(s):  
Taylor Instability ◽  
Wave Numbers ◽  
Rayleigh Taylor Instability

Rayleigh-Taylor Instability of a Shock Accelerated Gas Water Interface

2001 ◽  
Author(s):  
Xiao-Liang Wang ◽  
Motoyuki Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Taylor Instability ◽  
Gravitational Acceleration ◽  
Water Interface ◽  
Wave Impact ◽  
Growth Coefficient ◽  
Video Images ◽  
Rayleigh Taylor Instability ◽  
Interfacial Plane

Abstract Rayleigh-Taylor instability at a gas-water interface has been investigated experimentally. Such instability was produced by accelerating a water column down a vertical circular tube employing shock wave impact. Accelerations from 50 to 100 times gravitational acceleration with fluid depths from 125 to 250 mm were studied. The resulting instability from small amplitude random perturbations was recorded and later analyzed using high-speed video images. Cavity formation was observed in the middle of the gas-water interface soon after the shock wave impact; bubbles and spikes then developed across the rest of the interfacial plane. Measurements of the growth coefficient of the bubbles and spikes show that they are nearly constant over different runs.

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.

scholarly journals Ablation effects in weakly nonlinear stage of the ablative Rayleigh–Taylor instability

1996 ◽  
Vol 14 (1) ◽  
pp. 45-54
Author(s):  
Susumu Hasegawa ◽  
Katsunobu Nishihara
Keyword(s):  
Perturbation Theory ◽  
Mode Coupling ◽  
Wave Amplitude ◽  
Taylor Instability ◽  
Weakly Nonlinear ◽  
Effective Gravity ◽  
Nonlinear Stage ◽  
Excited Wave ◽  
Wave Numbers ◽  
Rayleigh Taylor Instability

Weakly nonlinear stage of the ablative Rayleigh-Taylor instability has been studied by the perturbation theory. Mode coupling of linear growing waves with wave numbers kA and kB drives new excited waves with wave numbers k0 (= kA ± kB, 2kA, 2kB). We have investigated time evolution of the excited waves and found that the ablation effect plays an important role even in the nonlinear stage to reduce amplitude of the excited waves. Differences between an ablation surface and a classical contact surface have been discussed. Dependence of the excited wave amplitude on the wavenumber k0, the ablation velocity va, and the effective gravity g is also investigated.

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.

Sign in / Sign up

Export Citation Format

Share Document