Great demands are made on the flow in water drains and fittings. Often measurements cannot adequatly capture the underlying phenomena. Maybe because water drains are implemented in a way that the position where sloshing or leakage occurs is not visible or such that the conditions under which these phenomena occur are unknown. Subsequent costs can be considerably high especially if sensitive electronics are involved.
Measurements in fittings are often compromising or can only be taken at very few postions. CFD-simulations are free oft these metering difficulties. Pressure loads on seals or sloshing phenomena in drains can be calculated with Volume-of-Fluid-simulations (VOF). Resulting geometry corrections can be tested virtually.
A purposeful reduction of pressure losses in fittings is possible. Self-cleaning can be improved by identification and elimination of dead spaces. Simulations with coupled fluid-structure-interaction (FSI) are suitable for diaphragm valves.