Of course, you're free to use it for whatever purpose you like (skydiving and blowing bubbles underwater come to mind).

So, type in your fluid viscosity and density, or choose from the liquids
offered. When you give it a critical velocity, Sphlow Java will tell
you the Reynolds number, friction factor and particle diameter and show
you the relevant point for the given particle density in the friction factor-Reynolds
number curve on the left. It will also plot diameters which rise/fall
at the same velocity for a range of particle densities in the curve on
the right. You may plot up to nine such velocity contours by selecting
a new curve number and entering a new velocity. If you change liquid
properties or *D-rho* graph limits, Sphlow Java will redraw all of
the velocity contours.

The red vertical line on the right indicates the liquid density. The starting point corresponds to nickel spheres in water.

f |
= | 4 mu g |rho-_{p}rho|_{f} |

Re |
rho_{f}^{2}u^{3} |

Re |
= | ,rho_{f} u D |

mu |

The model also assumes constant liquid and particle densities.
If these densities vary strongly with temperature, things will be somewhat
more complicated: if the liquid coefficient of thermal expansion (CTE)
is higher than that of the particle, there will be a range of densities
at which particles will be neutrally buoyant; if the particle CTE is higher
then it will always float or sink. Density also changes in porous
inclusions, *e.g.* porous titanium nitride in molten titanium, where
dissolving the dense nitride decreases a particle's average density but
filling a pore increases it. (See the paper
of Jean-Pierre Bellot and Alec Mitchell in the 12/1997
issue of *Metallurgical
and Materials Transactions* for details. Hey, while you're
there, check out my
paper too!)

Finally, the model assumes spherical inclusion particles. For
non-spherical particles, the friction factor will usually be smaller than
that of the smallest sphere containing the particle (always so in the case
of Stokes flow where *Re*<0.2), so velocity will be higher, and
this model will give a conservative velocity estimate for such particles.

Though Sphlow Java 0.2 has been successfully tested on Netscape 3.01 and 4.05 for Irix and Netscape 3.01 and 4.05 for PowerPC Mac, I have heard it doesn't work on Sandia Mac Netscape 3. My guess is that this is because the classes are not signed.

Get the source code here (distributed under GPL), and promote open source software!

Email compliments/complaints/comments, bug reports and suggestions for new liquids to me.