Double-average mean flow and local turbulence intensity profiles from PIV measurements for an open channel flow with rigid vegetation

MARTINO, R.; PATERSON, A.; PIVA, M.

SPRINGER

Lugar: Berlin; Año: 2012 vol. 12 p. 45 - 45

his contribution presents particle image velocimetry measurements for an open channel stationary uniform and fully developed flow of water over a horizontal flat bed of uniform glass beads in presence of a staggered array of vertical cylindrical stems. The main objective was to explore and quantify the influence of the stems-to-flowrelative submergence, hv/h, over the mean flow and local turbulence intensities. A comparison with measurements for the non-vegetated flowover the same granular bed is presented. Results indicate a remarkable influence of hv/h over the whole flowfield.The time-averagemean flowpresents a strong spatial variation in the layer of the flow occupied by the stems. The local velocity fluctuations are strongly affected by the presence of the stems, with regions in between the stems where they reach peaks that are several times larger than those encountered in the flow in absence of vegetation. The turbulence intensity profiles are noticeably different when compare