Abstract
Flow structures of a buoyancy jet in a grid turbulence field and in a flow field without a turbulence grid were investigated by flow visualization with a high speed camera and tracer technique. The present experiments were conducted for changing the mean velocity of a cross wind, jet velocity and temperature difference between the cross wind and the jet. The flow structures of the buoyancy jet were divided into three modes. Their modes were affected of interaction between the cross wind, the jet and the buoyancy. Bifurcation phenomena of the jet occurred when the effect of buoyancy force was dominated. The Strouhal number of vortices generated by the velocity shear was different in the each field. The streamwise length of vortex formation region just behind the jet exit was shorter in the grid turbulence than in the low turbulence field, because turbulence intensity affected on the process of vortex formation.
