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Intermittency and Anomalous scaling in turbulence - Victor S. L'vov ...

Intermittency and Anomalous scaling in turbulence - Victor S. L'vov ...

Intermittency and Anomalous scaling in turbulence - Victor S. L'vov ...

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Kolmogorov-41 fixed po<strong>in</strong>t<br />

¯vn =<br />

1<br />

[2(a − c)] 1/3 λ n/3<br />

is unstable, giv<strong>in</strong>g<br />

a r<strong>and</strong>om evolution<br />

of the “shell velocities” ⇒<br />

ζ p<br />

<strong>Anomalous</strong> exponents <strong>in</strong><br />

2.5<br />

⇓ Sabra shell model ⇓<br />

2<br />

1.5<br />

1<br />

0.5<br />

0<br />

Shell model<br />

p/3<br />

0 1 2 3 4 5 6 7<br />

p<br />

|u 11 |/ <br />

8.0<br />

6.0<br />

4.0<br />

2.0<br />

0.0<br />

0.0e+00 2.0e+06 4.0e+06 6.0e+06 8.0e+06 1.0e+07<br />

timesteps<br />

<br />

<br />

Let S3(kn) ≡ Im un−1unun+1∗ . Exact:<br />

S3(kn) =<br />

1<br />

2kn(a − c)<br />

S2p(kn) ≡ <br />

|un| 2p<br />

<br />

− ɛ + δ( c<br />

a )n , ζ3 = 1 .<br />

∝ k −ζ2p<br />

n<br />

.<br />

8

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