This regime takes place at r = 890.
The grafics, spectrum and phase diagram displays a chaotic 
character of this mode. The flow has low frequency on time with 
high-frequency oscillations. The vortexes structure (four vortexes) 
chaotic in time is birth and death. The lifetime of this vortex 
structure is a random quantity, distributed under the normal law.
Basically calculations were conducted at r=1000, r=Ra/Racr, 
Pr=2, Racr=657.5. Ra and Pr there are numbers of the Raleigh 
and Prandtl. The calculations were conducted up to r=3000, at 
these values of number r the random flow regime was supervised.