我一直对于low-mach-assumption flows 感到困惑。
using the low-Mach-number assumption, where the acoustic interactions and compressibility effects are eliminated.
low Mach-number flow / Pseudo-incompressibility:
The low Mach-number constraint can be derived from the compressible Euler equations using scale analysis of non-dimensional quantities.
The restraint, like the previous in this section, allows for the removal of acoustic waves, but also allows for large perturbations in density and/or temperature.
The assumption is that the flow remains within a Mach number limit (normally less than 0.3) for any solution using such a constraint to be valid.
Again, in accordance with all incompressible flows the pressure deviation must be small in comparison to the pressure base state.