Effect of a lip attached on one side of a two-dimensional nozzle upon free plane jet

Abstract

This study deals with the free jet from an asymmetrical two-dimensional nozzle whose asymmetry is introduced by a lip attached on one side of the nozzle. Experiments are conducted for three Reynolds numbers; 1000, 3000 and 6000. The aspect ratio of the nozzle exit is fixed at 300, which can be large enough to research the fundamental behaviour of a plane jet. In order to clarify the effect of the lip length, the lip length l varies in a wide range of 0 – 20h, where h denotes the height of the nozzle exit. Then, the authors show such basic characteristics of the jet as mean-velocity and turbulence-intensity profiles at various downstream sections, which suggest a potential in the control of a plane jet especially concerning its deflection angle in far downstream, which vibrates with l. Besides, the authors reveal negligible Reynolds number effects more than 3000, and propose an empirical formula to predict the deflection angle.

Keywords

• jet
• flow control
• two-dimensional flow
• nozzle
• air conditioning
• air curtain