- Explain why the viscosity of a liquid
decreases while that of a gas increases with a temperature rise.
The following is a table of measurement for a fluid at constant
temperature.
Determine the dynamic viscosity of the fluid.
[4.98 N/m2]
| du/dy
(rad s-1) |
0.00 |
0.20 |
0.40 |
0.60 |
0.80 |
| t (N m-2) |
0.00 |
0.01 |
1.90 |
3.10 |
4.00 |
- The density of an oil is 850 kg/m3.
Find its relative density and Kinematic viscosity if the dynamic
viscosity is 5 x 10-3 kg/ms.
[0.85, 1.47 x10-6 m2/s]
- The velocity distribution of a viscous
liquid (dynamic viscosity m = 0.9 Ns/m2) flowing over a
fixed plate is given by u = 0.68y - y2 (u is velocity in
m/s and y is the distance from the plate in m).
What are the shear stresses at the plate surface and at y=0.34m?
[0.612 N/m2, 0]
- 5.6m3 of oil weighs 46 800 N.
Find its mass density, r, and relative density, g.
[852 kg/m3, 0.852]
- From table of fluid properties the
viscosity of water is given as 0.01008 poises.
What is this value in Ns/m2 and Pa s units?
[0.001008 Ns/m2]
- In a fluid the velocity measured at a
distance of 75mm from the boundary is 1.125m/s. The fluid has absolute
viscosity 0.048 Pa s and relative density 0.913. What is the velocity
gradient and shear stress at the boundary assuming a linear velocity
distribution.
[15 s-1, 0.720 Pa]
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