Vortex Ring Model Research Articles

Vortex-ring model of Bose condensation

The partition function of the interacting Bose fluid is represented by an integral over function space and is evaluated approximately by an extension of the saddle-point method. In this way a vortex-ring model is derived from first principles. The superfluid phase of the Bose fluid is represented by a uniform field with a small number of quantized vortex rings of small circumference. In the normal phase the field is in a state of stationary homogeneous turbulence on a microscopic scale. The model leads to a combinatorial problem which, when solved approximately, gives a specific-heat exponent α = 1 3 . The analogy with the droplet model of condensation is discussed.

Stereo photogrammetry of cumulonimbus clouds

AbstractA technique is described for stereo photogrammetry of clouds. Movie cameras are set up on a ground baseline 5·6 km long. Time‐lapse films are made with a frame interval of 3 s. The analysis involves the super‐imposition of stereo pair images of the cloud, with advantages over methods previously used.Measurements are presented of an Alberta hailstorm, and estimates are made of horizontal divergence near the cloud tops, and mass flux. Measurements and calculations imply that the ring vortex model of the circulation in small cumulus tops is applicable to some large hail‐bearing storms, and that little or no net mass transfer occurs through the caps of rising cloud towers.