Velocity and turbulence measurements downstream of a sill followed by a rigid apron were performed. Three runs were conducted at different scouring stages: flat bed, 50% of the maximum scour depth and 100% of the maximum scour depth. For all the scouring stages, the vertical distribution of the horizontal velocity compo-nent, measured over the rigid apron, was found to be similar to a wall jet. When the bed is flat, the wall jet ve-locity distribution changes into a free surface velocity distribution, as the distance from the apron increases. When a scour hole develops downstream of the apron, the wall jet velocity distribution changes into an “asymmetric free jet” velocity distribution, till the abscissa of the maximum scour depth. Turbulence intensi-ties, along both the vertical and the horizontal axis, were found to decrease as the distance from the sill in-creased, for all the scouring stages. A similar behavior was observed for dimensionless Reynolds stresses over a flat bed. When a scour hole develops downstream of the apron, dimensionless Reynolds stresses show posi-tive values close to the bottom both inside the scour hole and downstream of the dune.

Adduce, C., Sciortino, G., Mele, P. (2007). Velocity and turbulence measurements in a scour hole at different scouring stages. In Proceedings of XXXII IAHR Conference.

Velocity and turbulence measurements in a scour hole at different scouring stages

SCIORTINO, Giampiero;
2007-01-01

Abstract

Velocity and turbulence measurements downstream of a sill followed by a rigid apron were performed. Three runs were conducted at different scouring stages: flat bed, 50% of the maximum scour depth and 100% of the maximum scour depth. For all the scouring stages, the vertical distribution of the horizontal velocity compo-nent, measured over the rigid apron, was found to be similar to a wall jet. When the bed is flat, the wall jet ve-locity distribution changes into a free surface velocity distribution, as the distance from the apron increases. When a scour hole develops downstream of the apron, the wall jet velocity distribution changes into an “asymmetric free jet” velocity distribution, till the abscissa of the maximum scour depth. Turbulence intensi-ties, along both the vertical and the horizontal axis, were found to decrease as the distance from the sill in-creased, for all the scouring stages. A similar behavior was observed for dimensionless Reynolds stresses over a flat bed. When a scour hole develops downstream of the apron, dimensionless Reynolds stresses show posi-tive values close to the bottom both inside the scour hole and downstream of the dune.
88-8940-506-6
Adduce, C., Sciortino, G., Mele, P. (2007). Velocity and turbulence measurements in a scour hole at different scouring stages. In Proceedings of XXXII IAHR Conference.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/181353
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