Turbulence in a Cylindrical Container of Argon near Threshold of Convection

Abstract

We present measurements and pattern visualization of convection in a cylindrical container at low Prandtl number. We demonstrate that the weak turbulence previously detected in this situation is clearly an erratic wandering of rolls. We show that the transition from a stationary to a time-dependent pattern involves spontaneous nucleation of dislocations. We analyze this phenomenon in relation to the skewed varicose instability.