Water Engineering Research

Korea Water Resources Association (한국수자원학회)
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CHARACTERISTlCS OF PLANE JETS IN THE TRANSITION REGION

  • Seo, Il-Won (Prof., Dept. of Civil Engineering, Seoul National Univ.) ;
  • Ahn, Jung-Kyu (Grad. Student, Dept. of Civil Engineering, Seoul National Univ.) ;
  • Kwon, Seok-Jae (Grad. Student, Dept. of Civil Engineering, Seoul National Univ.)
  • Published : 2002.07.01
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Abstract

In this study, laboratory experiments have been performed to investigate characteristics of the velocity fields and turbulence for non-buoyant plane jet in the vicinity of the jet nozzle using PIV system. The experimental results show that, in the transition region, the lateral velocity profile is in good agreement with Gaussian distribution. However, the coefficient of Gaussian distribution, $\K_{u,}$, decreases with longitudinal distance in the transition region. The existing theoretical equation for the centerline velocity tends to overestimate the measured data in the transition region. A new equation for the centerline velocity derived by incorporating varying $k_{u}$ gives better agreement with the measured data than the previous equation. The results of the turbulence characteristics show peak values are concentrated on the shear layers. The Reynolds shear stress profile shows the positive peak in the upper layer and negative peak in the lower layer. The turbulent kinetic energy also provides double peaks at the shear layers. The peak of the Reynolds shear stress and the turbulent kinetic energy increases until x/B=8, and then it decreases afterwards.s.

Keywords

References

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