Cleanup for SPH
nanoFluidX does not require the same amount of cleanup for smoothed-particle hydrodynamics (SPH) as traditional CFD code, or even a FEM structural code.
The geometry needs to be watertight and not allow leaks. However, watertight does not mean that the geometry needs to be connected or equivalenced. Small gaps can be present, so long as they are smaller than the particle spacing (dx).
De-featuring and removal of fasteners/small parts is not recommended, since they can be beneficial and avoid extra cleanup steps. For example, Figure 1 shows a sump drain is sealed by presence of sump plug and washer. This requires no cleanup or editing.
Extract Facets versus Initial Mesh
Both functions can be used to create a CAD tessellation. Extract Facets is the preferred route, as it is significantly faster. Initial Mesh is offered for legacy continuity. There is more control over the mesh, but it is much slower.