Some Details of the Structure of an Axisymmetric Confined Jet With Backflow

Abstract

The approximate theory of confined jets, as shown in earlier papers [1, 9, 12] is applicable to the case of an axisymmetric jet with backflow. The assumptions usually made, however, are not valid downstream of the core of the recirculation center; the authors have made measurements of the mean and fluctuating velocities and have developed a method of visualization of the instantaneous flow patterns. Because of the high turbulence levels, any future extension of the theory of the region downstream of the recirculation center should allow for the variation in secondary-stream energy, the hitherto neglected fluctuation terms, and the variation of a shear-stress coefficient along the duct axis.