Accutech ’s software package FluidFlow3 satisfies the steady-state design requirements and the program Hytran the water hammer requirements but until recently these have been quite separate programs. Now it is possible to export the FluidFlow3 steady-state model direct into Hytran. This linking of the two programs provides an integrated approach to the design and analysis of water and wastewater pipe flow systems.
Both programs provide an intuitive graphical user interface. FluidFlow3 allows a schematic flowsheet representation of the pipe system which can be annotated with both input data and calculated results. This, plus charts showing the performance of line equipment such as pumps, allows immediate interpretation of system performance. The model can then be exported to Hytran.
Hytran’s display of the pressure transients shows both the position-dependent transient pressures along the pipeline (the propagation of the pressure wave with flow direction changes are actually shown in real-time) as well as the time-dependent pressures at selected locations.
The screen image mosaic below shows a simple pipe flow system consisting of a single pump discharging via 2,250m of 400mm steel pipe to a reservoir at an elevation 40m above the pump. The upper image is the flowsheet schematic from FluidFlow3 and the image bottom right shows the steady-state performance of the pump – capacity, system and efficiency curves. Exporting this model to Hytran and solving for pump trip generated the image bottom left. This shows the time-dependent pressures at the pump. After 10s of steady-state running, the pump tripped and pump head immediately fell. At 30s after pump trip there was a significant spike in pressure at the pump. This was due to column separation at the 30m elevation high point in the line. Column separation and re-join continued with the peaks gradually attenuating due to friction in the line.