Aggregation and Breakup of Particles in a Shear Flow

Evaluation of oscillating grids and orbital shakers as means to generate isotropic and homogeneous small‐scale turbulence in laboratory enclosures commonly used in plankton studies

“…For example, shaker tables have traditionally been used as bioreactors, to maximize the growth of cell cultures or other biological processes (e.g., Büchs 2001 and references therein), but they are also routinely used in fields not directly related to biology, such as dispersion of oil contaminants (NRC 2005). Couette cylinders are used as viscosimeters and for the study of particle aggregation under shear flow (e.g., Serra et al 1997). Oscillating grids, a favorite of fluid dynamics experiments, have been extensively used in the study of sediment dynamics and mixing in stratified fluids (e.g., Rouse and Dodu 1955, Thompson and Turner 1975, Hopfinger and Toly 1976.…”

The effect of shear on colloidal aggregation and gelation studied using small-angle light scattering

“…In previous shear experiments the particles first aggregated due to shear, however, these aggregates eventually have either fragmented due to shear [2][3][4][5][6], restructured [6][7][8][9][10] or have experienced both fragmentation and restructuring [10][11][12]. For example, Serra et al [2] studied the effect of continuous shear flow on the mean aggregate size.…”

“…For example, Serra et al [2] studied the effect of continuous shear flow on the mean aggregate size. They used polystyrene particles with diameters of 2 µm and 5 µm.…”

Effect of hydrodynamics factors on flocculation processes in estuaries

“…The flocculation process mainly occurs in the very low salinity region (between 1 and 2.5 ppt) (Wollast 1988), and it is affected by hydrodynamic changes which can alter the suspended sediment particle by modifying its effective particle size, shape, porosity, density and composition. Numerous studies have been carried out to investigate the flocculation phenomenon in the laboratory, such as (Serra et al 1997;Manning and Dyer 1999;Mikes et al 2004;Maggi 2005) and in situ (Fennessy et al 1994;Syvitski et al 1995;van Leussen and Cornelisse 1996). Due to the complexity of the natural system, many simplifications are made in laboratory studies in order to control the different variable parameters in the flocculation process.…”

“…Four different devices, namely the jar test (Mikes et al 2004), annular flume , sedimentation column and turbulence grid (Maggi 2005), and the Couette device with a video camera system (Serra et al 1997;Serra and Casamitjana 1998) have been used for generating turbulence and flocculation in laboratory experiments. The development of the latter technology (video technology) has allowed obtaining both floc size and settling velocity spectra.…”