The Limit Deposit Velocity model, a new approach

Title:

The Limit Deposit Velocity model, a new approach

Creator:

Miedema, Sape A. and Ramsdell, Robert C.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:61e338b0-bb44-4be3-97c6-b8d96fab89ce
uuid:61e338b0-bb44-4be3-97c6-b8d96fab89ce
doi:10.1515/johh-2015-0034

Subject:

critical velocity, Limit Deposit Velocity, slurry transport, and Newtonian fluid

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

In slurry transport of settling slurries in Newtonian fluids, it is often stated that one should apply a line speed above a critical velocity, because blow this critical velocity there is the danger of plugging the line. There are many definitions and names for this critical velocity. It is referred to as the velocity where a bed starts sliding or the velocity above which there is no stationary bed or sliding bed. Others use the velocity where the hydraulic gradient is at a minimum, because of the minimum energy consumption. Most models from literature are one term one equation models, based on the idea that the critical velocity can be explained that way. Here the following definition is used: The critical velocity is the line speed below which there may be either a stationary bed or a sliding bed, depending on the particle diameter and the pipe diameter, but above which no bed (stationary or sliding) exists, the Limit Deposit Velocity (LDV). The way of determining the LDV depends on the particle size, where 5 regions are distinguished. These regions for sand and gravel are roughly; very small particles up to 0.014-0.040 mm (d < δv), small particles from δv-0.2 mm, medium particles in a transition region from 0.2-2.00 mm, large particles > 2 mm and very large particles > 0.015·Dp. The lower limit of the LDV is the transition between a sliding bed and heterogeneous transport. The new model is partly based on physics and correlates well with experiments from literature.

Language:

Slovak

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

273-286

Source:

Journal of hydrology and hydromechanics | 2015 Volume:63 | Number:4

Harvested from:

CDK

Metadata only:

false