the effect of the particle size distribution on non-newtonian turbulent ...

Chapter 4 Results and Analysis Page 4.12
25rnm pipeline (as outlined in Chapter 2) and are presented in Table 4.II toge<strong>the</strong>r with <strong>the</strong>
pseudo-shear diagram <strong>of</strong> <strong>the</strong> rheology <strong>of</strong> <strong>the</strong> test sets for kaolin clay, mixture 1 and mixture
2 in Figure 4.13 to Figure 4.15.
The rheological parameters obtained were used to analyze <strong>the</strong> test data using <strong>the</strong> <strong>the</strong>oretical
models mentioned in <strong>the</strong> literature review.
* - Sive rheoloo ..y for kaolin onl
Table 4.II: Summary <strong>of</strong> Slurry Properties
No Test Set Slurry c,,(%) TycPa) K(Pa.s O ) n S,
I Sivel * Kaolin/Quartz 7,L 4,89 0,2991 0,4840 2,22
3K 10 Kaolin 7,00 9,14 0,0676 0,645E 2,60
4K 20 Kaolin 6,16 5,80 0,0176 0,8154 2,60
5RF 10 Kaolin/Rock Flour 9,6, 3,68 0,0132 0,9474 2,60
6RF_20 Kaolin/Rock Flour 11,00 3,91 0,0105 0,9720 2,60
7RF_30 Kaolin/Rock Flour 13,29 5,53 0,0194 0,964E 2,60
8S 10 Kaolin/Rock Flour/Sand 16,4, 5,82 0,1413 0,557, 2,65
9S 20 Kaolin/Rock Flour/Sand 19,43 5,48 0,1239 0,6363 2,65
10 S_30 Kaolin/Rock Flour/Sand 23,86 8,02 0,1350 0,5911 2,65
4.4 VISCOUS SUB-LAYER
y
The viscous sub-layer thickness can be predicted using <strong>the</strong> Newtonian approximation and <strong>the</strong>
Wilson & Thomas (1985,1987) and Slatter (1994) models. Figure 4.16 to Figure 4.18 show
<strong>the</strong> relationship between wall shear stress and viscous sub-layer thickness for <strong>the</strong> first test
sets <strong>of</strong> kaolin clay, mixture I and mixture 2 respectively. The Maude & Whitmore (1958)
prediction <strong>of</strong> <strong>the</strong> viscous sub-layer thickness has been included in <strong>the</strong> figures. Figure 4.18
shows that at <strong>the</strong> higher wall shear stress values, <strong>the</strong> viscous sub-layer thickness is less than
<strong>the</strong> diameter <strong>of</strong> <strong>the</strong> larger <strong>particle</strong>s. As discussed in Chapter 2, <strong>the</strong> <strong>particle</strong>s must <strong>the</strong>refore
have an obstructing <strong>effect</strong> on <strong>the</strong> viscous sub-layer thus influencing <strong>the</strong> turbulent flow
behaViour.