Abstract
Transverse jet from elevated source is found in various environmental and industrial field which include smoke exhausting from stack into atmosphere and sewage water disposal in deep-ocean. The experiment is carried out in water tunnel using flow visualization and Laser Doppler Velocimetry. Analysis has been performed for axisymmetric round jet of aspect ratio of 9.0 with the velocity ratio varying up to 2.5 at Reynolds number (based on free stream crossflow velocity and jet external diameter) of 1000. Result shows the formation of different jet shear layer vortices with varying velocity ratio are: (i) clockwise-downwash vortices (velocity ratio less than 0.3), (ii) delayed-regular-clockwise vortices (between 0.3 to 0.7), (iii) regular-clockwise vortices (between 0.7 to 1.4) at the lee side of the jet shear layer, (iv) irregular-anticlockwise vortex at the upstream along with clockwise vortices at the lee side of the jet shear layer that together forms mushroom vortices (between 1.4 to 1.9) and (v) regular-mushroom vortices (above 1.9). The other vortices found are stack-end vortex (less than 0.9) in the wake near free end, upright vortices (above 0.9) in jet-wake and hairpin vortices (between 0.3 to 0.6) in downstream which is the stretched part of evolving shear layer.
