.Modelica.Fluid.Types.Roughness .Modelica.Fluid.Types.RoughnessThis Real type defines the absolute roughness of the inner surface of a pipe or fitting, i.e., the absolute average height of surface asperities. It has usually to be estimated. In [Idelchik 1994, pp. 105-109, Table 2-5; Miller 1990, p. 190, Table 8-1] many examples are given. As a short summary:
| Type of pipe | Roughness | |
| Smooth pipes | Drawn brass, copper, aluminium, glass, etc. | 0.0025 mm |
| Steel pipes | New smooth pipes | 0.025 mm |
| Mortar lined, average finish | 0.1 mm | |
| Heavy rust | 1 mm | |
| Concrete pipes | Steel forms, first class workmanship | 0.025 mm |
| Steel forms, average workmanship | 0.1 mm | |
| Block linings | 1 mm | |
type Roughness = Modelica.Icons.TypeReal(final quantity = "Length", final unit = "m", displayUnit = "mm", min = 0);