Investigation of Unladen and Fiber-Laden Coaxial, Round Water Jets

Coaxial jets are extensively used in industrial and biomedical applications. They consist of inner and outer jets and exhibit wake or shear layer instabilities depending on the ratio between the outer and inner jet exit velocity, ru. The first part of this research focuses on unladen coaxial jet flows and in particular the effect of increasing Reynolds number on the spatial distributions of mean velocities, Reynolds stresses, and terms of the turbulent kinetic energy budget were evaluated. Measurements were performed using time-resolved, planar particle image velocimetry (PIV) at three values of ru. In addition, vortex characteristics in the near-field of the coaxial jet were analyzed based on the vorticity, and swirling strength distributions. The second part of this research focused on the interaction between inertial, nylon fibers and the vortices in the near-field of a coaxial water jet.