Linear plots are not appropriate

However, many times the natural behavior of the model is not linear or polynomial.  For example we will soon find that pressure driven flow in a pipe gives f=16/Re as an exact solution for laminar flow and f=0.079 f-.25 as an approximate relation for turbulent flow.  How can we plot these?

[Graphics:../Images/log_log_gr_11.gif]

[Graphics:../Images/log_log_gr_12.gif]

We don't see any values (not too useful for reading and getting values off of, what if the range is smaller?

[Graphics:../Images/log_log_gr_13.gif]

[Graphics:../Images/log_log_gr_14.gif]

Now we can see, but this is not a nice shape.

[Graphics:../Images/log_log_gr_15.gif]

[Graphics:../Images/log_log_gr_16.gif]

For the turbulent relation, again, the plot is ugly.  However, we realize that both relations are power laws. That is, the functional form involves just a product of a coefficient and the variable to some power. (often times this is all we need).
So consider the manipulation.


Converted by Mathematica      June 19, 2000