Introduction Forcings Observations Atmospheric Turbulence Ocean Turbulence Dimensional Analysis

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Introduction Forcings Observations Atmospheric Turbulence Ocean Turbulence Dimensional Analysis Basic Equations Length Scales. Convective flows, Rayleigh-Nuselt numbers. Important parameters to consider in unstableflows Rayleigh Taylor Instab. The Atwood Number, A - PowerPoint PPT Presentation

Transcript of Introduction Forcings Observations Atmospheric Turbulence Ocean Turbulence Dimensional Analysis

1. Introduction2. Forcings3. Observations4. Atmospheric Turbulence5. Ocean Turbulence6. Dimensional Analysis7. Basic Equations 8. Length Scales

Convective flows, Rayleigh-Nuselt numbers

Important parameters to consider in unstableflows Rayleigh Taylor Instab.

• The Atwood Number, A

• The width of the mixing zone,

• The non-dimensional time,

• The Fractal Dimension

21

21

²cgAt2

tH/Ag

/logNlog

D

N D

1

1

Boussinesq Aproximation consiss

On neglegting inertial accelerations on

density fluctuations, but allowing the

Gravitational accelerations.

Baroclinic Vorticity

Shocks in AIR of He and Kr Balls, Which is Which ?

0 500 1000 1500

0

5

10

15

20

25

ODCi

tir #260 tir #262 tir #265point 1 point 2 point 3 point 4

x [c

m]

t [µs]

x3x4

x2

x1 krypton M=1, 2

0 500 1000 1500 20000

100

200

300

UODC

i

= 370 m/s Uec

= 45 m/s

U [m

/s]

t [µs]

tir #296 tir #257 tir #254point 1 point 2 point 3 point 4

x4 x1x2x3hélium

M=1,05

0 5 100

1

2

M = 1,05 < 5% M = 1,2 < 5% M = 1,5 < 5% M = 1,7 < 5%

L aval/R

0

t/t0

a)b)c)d)

VelocityMagnitude

Volumeof Fluid

VorticityMagnitude

0÷10÷0,33 -106÷84

min

max

Basic Turbulence

Basic Turbulence

Basic Turbulence

Basic Turbulence

 

• Stratification causes strong vertical anisotropy!• Redondo(1990)