envelope

20:46 Sep 2, 2017 

are only used for modelling / simulating a real bubble - it's the real-life bubble that has an "envelope" (the "computer simulation" is only trying to reproduce a model of it)

A real bubble is a volume of gas surrounded by an "envelope" i.e. liquid that is delimiting the bubble. It could be a thin liquid membrane, or it could a mass of liquid (like boiling water).

the "obvious" translation would be "l'enveloppe d'une bulle", and if you check the real-life use of "l'enveloppe d'une bulle" you'll find it describes the same physical reality.

Just because it's the literal translation doesn't make it automatically wrong. Not all literal translations are false friends.

19:59 Sep 2, 2017 

I could not find any entry about relating this term to computer graphics.

16:30 Sep 2, 2017 

You're saying this is a digital simulation - does that mean it's a term from computer graphics?

10:36 Sep 2, 2017 

From the very limited context that has been given, it seems that an air or gas bubble, initially circular when viewed from above, is trapped in a liquid at the bottom of a tank, along with solid particles of some material. The dynamics then moves the particles and changes the shape and position of the gas bubble.

The 'envelope' is just the surface of the (three-dimensional) bubble or the perimeter of the curve that contains the bubble when it is viewed from above.

More context would be helpful.

18:37 Sep 1, 2017 

They are doing some numerical simulations in this section. Please look at this link. There are some more definitions for this word than its common definitions
http://www.dictionary.com/browse/envelope

18:32 Sep 1, 2017 

The paragraph ends with these two sentences:

At the interface of the bubble and the water, a gap of two particle spacings was left. A region con- taining no particles was left above the free surface. A typical initial condition is shown in Fig. 9.

And, this is figure 9:

https://www.dropbox.com/s/3wox5698oa327be/File Sep 01, 22 59...

17:05 Sep 1, 2017 

This is difficult to answer, because an envelope is simply something that envelops or covers. Do you have a diagram, by any chance?