MATHCAD 3D avi
Who says you can't display 4 dimensions on a CRT display. R^{2}
Controls has done lot's of modeling. In order to explain how a model works
XY type graphs can be very helpful. Even simple models can involve
several variables and to see how they are related 3D graphs literally add a new
dimension to a simple XY plot. Excel is not so good for making 3D graphs
unless you have a graphing "add in" like AXUM. MathCAD however
provides an additional degree of freedom by allowing the animation of a
worksheet. When applied to a 3D graph, the results can be quite revealing
if the models can output the data in a suitable form. Imagine a tablecloth
flowing over the edge of a falling object and you get the picture. MathCAD
and AXUM are available from http://www.mathsoft.com.
 AVI #1 is R^{2} Controls Logo but animated  This is a model of
the gross profit in $/Day for a distillation column at a gas plant in
Louisiana. The XAxis is the isobutane in the nbutane product, the
Yaxis is the nbutane in the more valuable isobutane product. The
Zaxis is profit. The downward spike in the graph of R^{2}
Controls logo is a result of enormous energy costs as the products approach
perfect purity.
Surface of increasing energy cost.avi
 AVI #2 is using the distillation column model as above but instead of
varying the energy cost we vary the relative value of the products.
isobutane sell price is gradually increased as the time axis. This
definitely shifts the optimum operating point.
Surface of increasing iso value.avi
 AVI #3 is the exact same surface as shown above except we animate a
contour plot rather than a surface plot. In many ways the contour plot
is more useful to see how the optimum operating point shifts with increasing
value of the isobutane product.
Contour of increasing iso value.avi
 AVI #4 Comes from a compressor project. As gas well pressure
declines it takes ever more Compressor power to recover a given quantity of
Gas. Imagine an Electric drive Compressor sucking gas out of a
well. The compressor power is expensive and limits how much gas can be
recovered. As well pressure drops more electric power is required to
recover the gas. Pick a price for electric power and you can see how
the optimal gas recovery drops as the well pressure declines (over a period
of years).
Optimization Contour of declining well pressure.avi
Note: these *.AVI files are about 1 MB each and may take a while to load if
you have a slow connection. You will also need a mediaplayer. You
can download Windows Media Player from http://microsoft.com
