[Diele]

Hey guys,

A laser beam acts on the surface of a spherical liquid droplet to produce plasma, and the droplet is deformed and moves in the opposite direction of the laser incident. It has been pointed out in the literature that the dropper deformation after the laser action is an incompressible flow. Can our existing compressible flow code be used to deal with this incompressible flow?

[CornelisLely]

"incomprehensible flow" haha thats a good description

Yes you can change your code to make the density of the fluid only dependent on temperature, instead of being dependent on pressure and temperature. Practically, this will make your flow incompressible or incomprehensive as you say

[LuckyTran]

The "literature" is simply wrong. All flows are compressible. Incompressible flows violate Einstein's special theory of relativity. There is no reason to force a compressible code to act like an incompressible storyboard for the sake of matching someone else's wrong conclusion.

[sbaffini]

Originally Posted by Diele

Hey guys,

A laser beam acts on the surface of a spherical liquid droplet to produce plasma, and the droplet is deformed and moves in the opposite direction of the laser incident. It has been pointed out in the literature that the dropper deformation after the laser action is an incompressible flow. Can our existing compressible flow code be used to deal with this incompressible flow?

Physics says that all the materials, especially fluids, are compressible to a certain extent. Numerics doesn't really like that, because of the implications on the time scales.

But, physics apart, all the modern codes now have the capability to run in a mixed way (some zone incompressible, some others not) starting from a fully compressible formulation. In the same way, a modern fully compressible code has the capability to run fully incompressible.

Take home messages:

1) learn about the capabilities of modern CFD codes and how they work in different compressibility scenarios

2) forget about the numerics and focus on your actual physics, which can be probably handled by a modern CFD code