| Coriolis | Incompres- sibility | Relative accelaration | Advection | Viscosity | Electroma- gnetic force | Conduc- tivity | Divers | |
| Eq. Helmholtz | x | x | x | - | - | - | - | Poincaré motion |
| Geostrophic Fluid | x | x | - | - | - | - | - | Taylor Column |
| Eq. Poincaré | x | - | - | - | - | - | - | |
| Boussinesq approximation | x | - | x | - | - | - | - | Eulerian density neglected except |
| Eq. Greenspan | x | x | x | - | x | - | - | in terms involving gravity |
| Other possibilities | ||||||||
| (1) | - | - | x | - | x | - | x | Non-rotating |
| (2) | x | - | x | - | x | - | x | |
| (3) | x | - | x | x | x | - | x | Eventually turbulence |