Compressibility and divergence-free flow

1. Nov 27, 2007

smarras

Hi there, I'd like to know if, under the conditions of thermal flows (viscous, conductive) and low Mach numbers (< 0.3), it is formally/conceptually correct to affirm that "non-divergence is only necessary condition for incompressibility"

Thank you very much in advance

S.

2. Dec 18, 2007

sayak

As far as I am aware Div(V)=0 is the only condition for incompressible flows. If Div(V) is not zero, flow is not incompressible and vice versa. So necessary and sufficient.

3. Dec 18, 2007

smarras

Hi there Sayak, thank you very much for replying!
All the best

Simone