Mass transfer between the vortex ring and the surrounding fluid, when the density of the fluid in the vortex is less than outside it

The mass transfer between the atmosphere of a vortex ring and the surrounding liquid was studied by the shadow method in the case, when the density of the liquid in the vortex is less than outside it. The obtained results were compared with experiments on the motion of vortex rings containing a fluid denser, than the surrounding fluid. The qualitative effects of changing the shadow image is established to be the same in both cases. The characteristic path and time of exchange are determined by analyzing of shadow images in depending on the speed and magnitude of the density difference.