Scalar transport and mixing in turbulent stratified shear flow

✍ Scribed by Frank G. Jacobitz

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 303 KB
• Volume: 21
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(00)00042-4

✦ Synopsis

In this study, the evolution of the velocity ®eld and scalar concentration ®elds in stably strati®ed shear ¯ow is studied using direct numerical simulations. Two cases with vertical mean shear and horizontal mean shear are compared. In both cases, the growth of the turbulent kinetic energy weakens as the Richardson number is increased. However, the horizontal shear case shows a stronger growth of the turbulent kinetic energy than the vertical shear case for a given Richardson number. The ordering of the velocity components was found to change from streamwise b horizontal b vertical in the vertical shear case to streamwise b vertical b horizontal in the horizontal shear case. The ¯uctuation level of a passive species variable with a vertical mean gradient was observed to be stronger in the horizontal shear case. The ratio of the vertical turbulent eddy diusivity to the horizontal turbulent eddy diusivity was found to be larger in the horizontal shear case.