Velocity field measurements of a laminar thermal

Abstract

Tracer particle path photographs of a rising isolated laminar thermal injected from a small source are presented. The presence of a velocity wake was clearly observed. The streaks of the tracers were sufficiently clear to deduce the velocity and vorticity fields. There is some indication that the velocity field approached a similarity state after an initial development distance. The vorticity distribution, calculated from the velocity field, was diffuse with no evidence of a distinctive core. Near the symmetry axis, the vorticity varied almost linearly with the radial coordinate and was independent of the axial coordinate. In the far field, the vorticity decreased monotonically.