A collection of visualizations that convey a basic understanding of buoyancy-driven mixing is presented. Buoyancy-driven mixing resulting from the Rayleigh-Taylor instability occurs in a unstably stratified flow when a heavy fluid rests above a light fluid. The difficulty of creating an unstable density stratification and repeatable fluid interface has made studying the Rayleigh-Taylor instability a challenging task. Our experiments utilize a water channel and most recently a gas channel (low speed wind tunnel). The experimental configuration allows unstable perturbations to develop into a mixing layer as they travel downstream. Thus resulting in a repeatable experiment and statistically steady flow. Various visualization techniques have been used to observe the development of the Rayleigh-Taylor instability. Visualizations using Nigrosene dye as a fluid marker are shown in the evolution of single and binary mode perturbations due to the Rayleigh-Taylor instability. In contrast, visualizations of the Rayleigh-Taylor instability developed from multi-mode perturbations are seen for the gas channel using both fog and smoke to visualize the flow. Together these techniques help provide an understanding for the nature and complexity of buoyancy driven mixing.

1.
Beale
J. C.
and
Reitz
R. D.
,
1999
, “
Modeling spray atomization with Kelvin-Helmholtz/Rayleigh-Taylor hybrid model
,”
Atomization and Sprays
, vol.
9
(
6
), pp.
623
650
.
2.
Lindl, J.D., 1998, Inertial Confinement Fusion: The Quest for Ignition and Energy Gain Using Indirect Drive, Springer-Verlag.
3.
Chandrasekhar, S., 1961, Hydrodynamic and Hydromagnetic Stability, Clarendon.
4.
Youngs
D. L.
,
1984
, “
Numerical simulation of turbulent mixing by Rayleigh-Taylor instability
,”
Physica D
, vol.
12
, pp.
32
44
.
5.
Read
K. I.
,
1984
, “
Experimental investigation of turbulent mixing by Rayleigh-Taylor instability
,
Physica D
, vol.
12
, pp.
45
58
.
6.
Dimonte
G.
and
Schneider
M.
,
1996
, “
Turbulent Rayleigh-Taylor instability experiments with variable acceleration
,”
Phys. Rev. E
, vol.
54
(
4
), pp.
3740
3743
.
7.
Andrews
M. J.
and
Spalding
D. B.
,
1990
, “
A simple experiment to investigate two-dimensional mixing by Rayleigh-Taylor instability
,”
Phys. Fluids A
, vol.
2
(
6
), pp.
922
927
.
8.
Lawrence
G. A.
and
Browand
F. K.
,
1991
, “
The stability of a sheared density interface
,”
Phys. Fluids A
, vol.
3
(
10
), pp.
2360
2370
.
9.
Snider
D. M.
and
Andrews
M. J.
,
1994
, “
Rayleigh-Taylor and shear driven mixing with an unstable stratification
,”
Phys. Fluids
, vol.
6
(
10
), pp.
3324
3334
.
10.
Ramaprabhu
P.
and
Andrews
M. J.
,
2004
, “
Experimental investigation of Rayleigh-Taylor mixing at small Atwood numbers
,”
J. Fluid Mechanics
, vol.
502
, pp.
233
271
.
11.
Koop, G.K., 1976, “Instability and Turbulence in a stratified shear layer,” PhD. Thesis, University of Southern California.
12.
Leicht, K., 1997, “Effects of Initial Conditions on Rayleigh-Taylor development,” MSc Thesis, Texas A&M University.
13.
Jacobs
J. W.
, and
Sheeley
J. M.
,
1996
, “
Experimental study of incompressible Richtmyer-Meshkov instability
,”
Physics of Fluids A: Fluid Mechanics
, vol.
8
(
2
), pp.
405
415
.
14.
Mueschke, N., Kraft, W., Andrews, M.J. and Jacobs, J., 2005, “Numerical Investigation of Singe-Mode Richtmyer- Meshkov Instability,” Proceedings 2005 ASME Fluids Engineering Division Summer Meeting and Exhibition, June 2005.
This content is only available via PDF.
You do not currently have access to this content.