Interaction of dense particles with stratified and turbulent environments.
The carrageenan is used at very low concentrations to form an imperceptible weak gel that prevents the large, dense particles of chocolate from sedimenting.
The spalling effect occurs in areas with large differences in density; particles of the denser tissue are spalled (thrown) into the less dense particles.
Preferential concentration is the tendency of dense particles in a turbulent fluid to cluster in regions of high strain (low vorticity) due to their inertia.
Partly fill the bowl with water and sprinkle dense particles such as sand or rice into the bowl.
The dense particles will quickly be swept into a neat pile in the center of the bowl.
The primary flow might be expected to fling the dense particles to the perimeter of the bowl, but instead the secondary flow sweeps the particles toward the center.
If we start with low flow rates small less dense particle attain their terminal velocites, and flow with the stream.
Suspended solids retained on a filter may remain in suspension if their specific gravity is similar to water while very dense particles passing through the filter may settle.
Alluvial placers are formed by the deposition of dense particles at a site where water velocity remains below that required to transport them further.