A head loss model for homogeneous slurry transport for medium sized particles

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Title:A head loss model for homogeneous slurry transport for medium sized particles
Creators:
Miedema, Sape A.; s dot a dot miedema at tudelft dot nl; Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
Journal or Publication Title:
Journal of Hydrology and Hydromechanics, 63, 1, pp. 1-12
Uncontrolled Keywords:slurry transport, homogeneous transport, viscous sub layer, mixing length

Abstract

Slurry transport in horizontal and vertical pipelines is one of the major means of transport of sands and gravels in the dredging industry. There exist 4 main flow regimes, the fixed or stationary bed regime, the sliding bed regime, the heterogeneous flow regime and the homogeneous flow regime. Of course the transitions between the regimes are not very sharp, depending on parameters like the particle size distribution. The focus in this paper is on the homogeneous regime. Often the so called equivalent liquid model (ELM) is applied, however many researchers found hydraulic gradients smaller than predicted with the ELM, but larger that the hydraulic gradient of liquid. Talmon (2011, 2013) derived a fundamental equation (method) proving that the hydraulic gradient can be smaller than predicted by the ELM, based on the assumption of a particle free viscous sub-layer. He used a 2D velocity distribution without a concentration distribution. In this paper 5 methods are described (and derived) to determine the hydraulic gradient in homogeneous flow, of which the last method is based on pipe flow with a concentration distribution. It appears that the use of von Driest (Schlichting, 1968) damping, if present, dominates the results, however applying a concentration distribution may neutralise this. The final equation contains both the damping and a concentration distribution giving the possibility to calibrate the constant in the equation with experimental data. The final equation is flexible and gives a good match with experimental results in vertical and horizontal pipelines for a value of ACv = 1.3. Data of horizontal experiments Dp = 0.05–0.30 m, d = 0.04 mm, vertical experiments Dp = 0.026 m, d = 0.125, 0.345, 0.560, and 0.750 mm.

Official URL: http://147.213.145.2/vc/vc1.asp

Title:A head loss model for homogeneous slurry transport for medium sized particles
Translated title:A head loss model for homogeneous slurry transport for medium sized particles
Creators:
Miedema, Sape A.; s dot a dot miedema at tudelft dot nl; Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
Uncontrolled Keywords:slurry transport, homogeneous transport, viscous sub layer, mixing length
Subjects:T Technology > TA Engineering (General). Civil engineering (General)
Divisions:Mathematics, Physics and Earth Sciences > Institute of Hydrodynamics > Journal of Hydrology and Hydromechanics
Journal or Publication Title:Journal of Hydrology and Hydromechanics
Volume:63
Number:1
Page Range:pp. 1-12
ISSN:0042-790X
Publisher:Institute of Hydrology of the Slovak Academy of Sciences and the Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic
Related URLs:
URLURL Type
http://avi.lib.cas.cz/node/55Publisher
ID Code:8405
Item Type:Article
Deposited On:13 May 2015 19:23
Last Modified:13 May 2015 17:23

Citation

Miedema, Sape A. (2015) A head loss model for homogeneous slurry transport for medium sized particles. Journal of Hydrology and Hydromechanics, 63 (1). pp. 1-12. ISSN 0042-790X

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