quote:I''m more trying to simulate the actions and see if the results approximate reality.
If I understand you correctly does this mean you want to make up a set of laws which have a similar effect to the actual physical laws?
Here is a random suggestion then (it''s probably quite slow but it might give you a few more ideas hopefully).
In 2D:
Divide your container in to equal size squares. Count the number of particles in each square. For each square determine which adjacent square has the fewest particles. Give the particles in your square a drift towards this square. If the square being analysed has the fewest particles then don''t change anything about them.
You''d have to tweak the numbers quite a bit e.g. consider the difference in number of particles when applying the drift, different square sizes.
This would give you a system of massy and unmassy regions and all the calculations can be scaled ofcourse producing a less reliable model for less divisions).
You could also consider all surrounding squares and calculate the drift based on the difference in particles for each one.
e.g. with a linear example for simplicity.
|-|-|-|
|1|X|2|
|-|-|-|
-----+X->
For the central square the total drift would be equal to the negative X drift = - (X-1)/X plus the positive X drift = (X-2)/X.
So if X was 3 the drift would be - (3-1)/3 + (3-2)/3 = -1/3.
Correct me if I''m wrong here but atoms/molecules in a fluid do not in general interact through gravitational or electrostatic means unless the ''fluid'' is at a _very_ low temperature (e.g. bose-einstein condensates).
So all the interactions are just collisions.
In a dense section of the fluid there will be more collisions and therefore more scattering. So this section will expand and eventually you will reach a macroscopic equillibrium.
A lot of crap there so please if I''ve said something stupid hit me :-)
-Meto / Karle
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