Flow Characteristics of a Plane Jet with an Extended Lip-Plate and Serrated Tabs

Abstract

We present the flow characteristics of a plane jet from a nozzle with an extended lip-plate and serrated tabs. The interaction between spanwise and streamwise vortices in the plane jet was studied experimentally. The nozzle has an extended lip-plate and serrated tabs in order to enhance the spanwise and streamwise vortices generated in the mixing layer. The extended lip-plate length of the nozzle L was changed from 0 to 10H (H: height of plane nozzle). Serried isosceles triangle tabs were placed on the upper or lower side of the nozzle exit. It is found that the increment of entrainment for the jet from a nozzle of L/H =2 without tabs is related to the self-excited spanwise vortical structure. The tabs suppress the formation of self-excited vortices in shear layers of the plane jet from a nozzle with an extended lip-plate.

Keywords

• jet
• plane nozzle
• flow control
• vortex
• self-excitation
• extended lip-plate
• serrated tab
• turbulent mixing
• flow visualization