Transversal and longitudinal mixing in compound channels

G. Besio, A. Stocchino, S. Angiolani, M. Brocchini

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)


An experimental campaign, based on particle image velocimetry (PIV) measurements of free-surface velocities, forms the basis for an analysis of the mixing processes which occur in a compound-channel flow. The flow mixing is characterized in terms of Lagrangian statistics (absolute dispersion and diffusivity) and of the related mean flow characteristics. Mixing properties strongly depend on the ratio rh between the main channel flow depth (hmc) and the floodplain depth (h*fp), and three flow classes can be identified, namely shallow, intermediate, and deep flows. In the present study the large time asymptotic behavior of the mixing characteristics is analyzed in terms of the absolute diffusivity in order to characterize typical values of longitudinal and transversal diffusivity coefficients. Various sets of experiments, which cover a wide range of the governing physical parameters, have been performed and the asymptotic values of the absolute diffusivity have been evaluated. The results are then compared with several studies of flow dispersion for both the longitudinal diffusivity coefficient and the transversal turbulent mixing coefficient. The present results highlight a stronger dependence of such coefficients with the flow-depth ratio than with the flow regime (Froude number).

Original languageEnglish
Article numberW12517
JournalWater Resources Research
Issue number12
Publication statusPublished - 2012
Externally publishedYes

ASJC Scopus subject areas

  • Water Science and Technology


Dive into the research topics of 'Transversal and longitudinal mixing in compound channels'. Together they form a unique fingerprint.

Cite this