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This gradient in the velocity profile contributes to the force that a floc experiencing roll-up feels. Flocs actually begin to roll up when the velocity at their edge exposed to the flow exceeds some critical value, which the settling velocity that the floc particle experiences. + The settling velocity of a floc particle is highly dependent on the floc 's diameter , its and floc density. Conversely, the critical velocity a floc experiences is dependent on floc diameter and the inner tube diameter.+ and the capture velocity of the system, among other things.
Theoretical Analysis of the Velocity Gradient
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