Von
K‡rm‡n Flows
¥ Geometrical ingredients: helicity
+ diff. rotation
Moffat, Cambridge UP, (1978)
¥ Laminar threshold : kinematic
simulations
Duddley James, Proc. R. Soc. Lond. A425 (1989)
MariŽ et al., Eur. Phys. J B33 (2003)
¥ turbulent threshold : DNS (Pm=1
down to 0.01)
Nore et al., Phys. Plasmas, 4, (1997)
Ponty et al., PRL 94 (2005)
mean
fluctuations
~ 50%