| SI.Length | dimension (from StraightPipe) | 4*crossArea/perimeter | Characteristic dimension (e.g., hydraulic diameter) |
| SI.Area | crossArea (from StraightPipe) | pi*dimension*dimension/4 | Cross-sectional flow areas |
| SI.Length | perimeter (from StraightPipe) | 4*crossArea/dimension | Wetted perimeters |
| SI.Length | length (from StraightPipe) | 1.0 | Pipe length |
| SI.Height | roughness (from StraightPipe) | 2.5e-5 | Average heights of surface asperities |
| SI.Area[nSurfaces] | surfaceArea (from StraightPipe) | {perimeter*length} | Area per transfer surface |
| SI.Angle | angle (from StraightPipe) | 0.0 | Vertical angle from the horizontal (-pi/2 < x <= pi/2) |
| SI.Length | dheight (from StraightPipe) | length*sin(angle) | Height(port_b) - Height(port_a) distributed by flow segment |
| SI.Length[nV] | dimensions (from GenericPipe) | 4*crossAreas./perimeters | Characteristic dimension (e.g., hydraulic diameter) |
| SI.Area[nV] | crossAreas (from GenericPipe) | pi*dimensions.*dimensions./4 | Cross sectional area of unit volumes |
| SI.Length[nV] | perimeters (from GenericPipe) | 4*crossAreas./dimensions | Wetted perimeter of unit volumes |
| SI.Length[nV] | dlengths (from GenericPipe) | ones(nV) | Unit cell length |
| SI.Height | roughnesses (from GenericPipe) | fill(2.5e-5, nV) | Average heights of surface asperities |
| SI.Area[nV,nSurfaces] | surfaceAreas (from GenericPipe) | [perimeters.*dlengths] | Discretized area per transfer surface |
| SI.Angle | angles (from GenericPipe) | fill(0, nV) | Vertical angle from the horizontal (-pi/2 <= x <= pi/2) |
| SI.Length | dheights (from GenericPipe) | dlengths.*sin(angles) | Height(port_b) - Height(port_a) |
| SI.Length | height_a (from GenericPipe) | 0 | Elevation at port_a: Reference value only. No impact on calculations. |
| SI.Length | height_b (from GenericPipe) | height_a + sum(dheights) | Elevation at port_b: Reference value only. No impact on calculations. |
| SI.Volume[nV] | Vs (from GenericPipe) | crossAreas.*dlengths | Unit volumes |
| SI.Volume | V_total (from GenericPipe) | sum(Vs) | Total volume of component |
| SI.Area[nV] | surfaceAreas_nVtotal (from GenericPipe) | {sum(surfaceAreas[1, :]) for i in 1:nV} | Total surface area for each volume node |
| SI.Area | surfaceArea_total (from GenericPipe) | sum(surfaceAreas_nVtotal) | Total surface area |
| Real[nV] | dxs (from GenericPipe) | dlengths/sum(dlengths) | Fractional lengths |
| SI.Length[nZ] | ths_wall (from PartialPipeWithWall) | | Specify wall thickness or drs |
| SI.Length[nR,nZ] | drs (from PartialPipeWithWall) | | Wall unit volume lengths of r-dimension |
| SI.Length[nR,nZ] | dzs (from PartialPipeWithWall) | | Wall unit volume lengths of z-dimension |
| SI.Length | th_wall | 0.01 | Wall thickness or specify dr |
| SI.Length[nR] | dr | fill(th_wall/nR, nR) | Wall unit volume lengths of r-dimension |
