Empirical Derivation Of Flow Paramaters Describing The Behavior Of A Novel Artificial Test Solid For Building Drainage Systems

The empirical investigation and development of a new drain-line carry test solid (DRG) for use in building drainage, waste and ventilation (DWV) system research is described. Through anecdotal evidence and during use on previous research, it was noticed that the ‘shelf life’ of the test solid used historically (NBS solid) was short and variability in results was large, making it problematic for use in extended investigative work. Further investigations revealed that the materials used in it’s construction were porous and osmosis would be a contributing factor to the variability observed, as would biofilm growth causing changes in the coefficients of kinetic and static friction. Furthermore, these effects would be regionally different according to how soft or hard the local water was when used to fill the solid.

This research is also timely in view of the changing (i.e. generally reducing) volume and energy of contemporary discharges through water conservation initiatives such as WaterWise. Modern materials and analysis techniques present an opportunity to update the NBS solid and develop a modern alternative for research. The results from laboratory tasting of the DRG solid compare favorably to the results from the NBS solid. Enhancements to the current mathematical description of the behaviour of a test solid used in a computer based simulation model (DRAINET) is proposed, creating the potential for extensive follow-on uptake of these results and use by other researchers and potentially for use as a standard.