GEOL8550
Clay Mineralogy Exercise #1
Create a spreadsheet that
calculates
the following:
1. Settling time (t) for a particle in a graduated cylinder
2. Settling time (t) for a particle in a centrifuge.
Use Stoke's Law to calculate the
time of
settling: Use units of (day:hr:min:s)
Allow the user to specify: (units in red)
a.
The
equivalent spherical diameter (esd) of the
particle (D cm and µm).
b.
The depth
from top of meniscus for case 1 (h cm).
c.
Density of
particle (dp g cm-3).
d.
Viscosity
of fluid (η centipoise or dyne s cm-1
or
g cm-1 s-1).
e.
Density of
fluid (dl g cm-3).
f.
Acceleration
due
gravity
for
case
1
(g
cm s-2).
g.
Time of
acceleration for case 2 (ta s).
h.
Time of
deceleration for case 2 (td s).
i.
Initial
distance from axis of rotation for case 2 (R1 cm).
j.
Final
distance from axis of rotation for case 2 (R2 cm).
k.
Angular
velocity of centrifuge for case 2 (N RPM and
revolutions per sec or Hz).
l.
Temperature
of
fluid
(T
degrees C)
if you want to modify viscosity term.
The
following spreadsheet syntax gives a proxy for water temperature versus
viscosity. It is a 3rd order polynomial fit to actual
published
data for water temperature versus viscosity (which means the equation
has no
theoretical basis, but it provides errors less than 5%).
For a
cell "A2" in a spreadsheet, which contains the temperature, you can
calculate the viscosity in cell "B2":
i.e., Let
A2 =
Temperature (T) of interest and viscosity (η) answer
is
returned in B2
as centipoise.
B2
=(-0.000001*A2*A2*A2)+(0.0003*A2*A2)-0.0343*A2+1.5598
Useful equations:
For case 1 from Moore and Reynolds
(1997):
For case 2 from Hathaway (1955):
