Resuspension of sediments by multiple jets

Resuspension of sediments in karstic lakes by multiple bottom-springs is mi micked using a laboratory experiment, wherein an array of axisymmetric vert ical jets are forced through a planar bed of noncohesive sediments. Three d ifferent types of flow evolution are identified namely, full deposition, wh ere all the suspended particles settle after initial transients, continuous reentrainment, where the particles remain in individual jet cores without deposition, and particle interface, where the sediments disperse in the ent ire bottom layer, forming a lutocline between the turbid lower layer and cl ear upper layer, regimes. Because of its practical relevance, special atten tion is given to the particle interface regime. A semiempirical criterion f or the appearance of this regime and an expression for the height of the re sulting lutocline are delineated. Velocity measurements indicate that the i ntensity of turbulence above the lutocline is determined by the nature of p article-flow interactions in the sediment layer, characterized by the parti cle Reynolds number.