Laminar Mixing Of Coaxial Streams PDF Download

The report presents the results of experimental and analytical investigations of the confined coaxial mixing of isoenergetic air streams. Both uniflowing and counterflowing secondary air streams are considered. Laminar and turbulent uniflow mixing are treated analytically. The results of experimental investigations of turbulent mixing are used to calculate the radial as well as the axial variations of eddy viscosity and the turbulent diffusion coefficient up to 25 jet diameters downstream of jet orifice. New expressions are developed to yield reliable values in regions of mixing where existing expressions become indeterminate. Special consideration is given to the case where the two streams have equal velocity. The experimental investigation of turbulent counterflow mixing shows that a toroidal shaped vortex is set up at the jet interface which gives rise to depressed static pressures. Over the range of parameters investigated, entrainment of fluid from the inner jet into the external stream takes place downstream of the vortex. (Author).