Turbulent Compound Annular Shear Layers

A similarity type of analysis has been applied to the developing zone of a co-flowing circular turbulent jet and it shows that the half width of the jet and the inner radius of the shear layer vary linearly with the axial distance from the nozzle. Using the linear variation of the length characteristics, the earlier equations of Squire and Trouncer have been simplified for computation. At four different velocity ratios, measurements were made of the growth of the inner and outer radii of the annular shear layer and the half width. The data show the linear variation of the length characteristics. From the experimental results the empirical coefficient c² was found to vary with the ratio of secondary stream velocity to the jet velocity. Experimental results are presented regarding the variation of the length of the potential core and the angle of the inner and outer edges of the shear layer with the velocity ratio.