1. A tube viscometer was used to measure the viscosity of a clay suspension at 20°C. The tube radius is 2.5 cm and length is 1 m The following data have been collected (see the Table on right). The shear rate at the wall can be approximated to be 4QzR3. Determine the theological parameters of this suspension if the fluid is a:
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:IP (Pa)
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Flow rate Q (cm° is)
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|
10.0
|
1.25
|
|
12.5
|
1.55
|
|
15.0
|
1.80
|
|
17.5
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2.05
|
|
20.0
|
2.55
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a. Newtonian fluid (use the model r if/ and determine ti)
b. Power-law fluid (use the model r K't and determine K and n
2. The data (see the Table on right) were obtained using a concentric cylinder rotational viscometer. The rotating inner cylinder was 60 mm high and 21 mm in diameter. The diameter of the stationary outer cylinder is 25 mm. Determine the theological parameters (Ty. K and n) for the following cases:
a. Assuming it as a Bingham fluid (use model
b. Assuming it as a power-law fluid (use model q =
(Note: use Equation [11] on page 108 of Lecture Note to calculate shear stress)
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RPM
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Torque. Nm
|
|
4
|
0.0048
|
|
S
|
0.0061
|
|
16
|
0.0071
|
|
32
|
0.0085
|
|
64
|
0.0106
|
|
128
|
0.0146
|
|
256
|
0.0197
|