抄録
The flow and mixing in transient laminar jets of CO2 emitted into an N2 stream were experimentally studied. Time-and space-resolved measurements of velocity and concentration were made by a laser Doppler velocimeter and by the laser Rayleigh scattering method in transient jets, together with visual studies by Schlieren photography. The results obtained are as follows. (1) Axisymmetric large scale ring vortices are formed successively in the jet and travel downstream. (2) Out ward or inward radial flow is induced downstream or upstream of each ring vortex, respectively. The vortex has the velocity of solid body rotation in the central part, and free vortex in the outer part of the vortex. (3) The surrounding gas (N2) is engulfed by the vortex to form the laminated layer which enhances micro-mixing in the molecular scale.
