Hydraulic Performance Validation of a 4.8L Low-Consumption Toilet Using CFD Simulation

Efficient water use in sanitary systems is essential for sustainability and design competitiveness. This study validates the hydraulic performance of a 4.8L low-consumption toilet using computational fluid dynamics (CFD) with OpenFOAM and ANSYS Fluent. The simulation focused on key hydraulic phenomena, including siphon action and water distribution over the bowl, following the INEN 3082 standard. The toilet geometry was developed using CAD and meshed with high refinement to ensure simulation accuracy. Two-phase Volume of Fluid (VOF) models captured the transient behavior of the flushing process, enabling analysis of siphon development and surface cleaning efficiency. Results demonstrated consistency between both software, with acceptable error margins in pressure and velocity fields, and confirmed the development of the siphon effect within five seconds, aligning with empirical expectations. The cost analysis revealed that OpenFOAM offers a highly cost-effective validation method from the first simulation, while ANSYS becomes economically viable with multiple simulations. This approach provides a sustainable alternative to experimental testing in toilet prototyping, reducing water and material waste while accelerating product development in the sanitary industry.