Effect of a standing baffle on the flow structure in a rectangular open channel

Abstract

The effect of an intermediate standing baffle on the flow structure in a rectangular open channel has been investigated by a three-dimensional acoustic Doppler velocimeter. Investigation of time-averaged velocity profiles at different streamwise positions reveals that the approach flow is fully developed upstream of the baffle. By analysing the space-averaged power spectra of streamwise velocity, a peak structure was observed in the upstream baffle region. Downstream of the baffle this peak structure has been alleviated by the baffle. The same analysis for the vertical component indicates the existence of a peak structure both up- and downstream of the baffle. Consequently, a baffle affects the streamwise energy dissipation but not the vertical energy dissipation.

Keywords:

• Acoustic Doppler velocimetry
• baffle
• power spectra
• spatial structure
• temporal structure

Acknowledgements

The authors are grateful to the Center of Engineering Education Development, Hokkaido University, for financial support and to present a part of the material in this paper. They deeply thank all those who provided them with useful assistance. They also thank the Center of Excellence in Energy Conversion, School of Mechanical Engineering and the Research deputy of Sharif University of Technology who supported this research.

Additional information

Notes on contributors

Hamidreza Jamshidnia

IAHR Member