Speaker
Description
Structure‑borne sound generated by wastewater pipesystems often dominates noise emissions from sanitaryinstallations in buildings. This noise is mainly caused byturbulent annular flow and by water impacts on inlets, tees,and bends. The water excitation, and thus the resultingstructural response, is treated as a stochastic process anddescribed by its power spectral density (PSD). A suitablemathematical model of PSD for the individual excitationsub‑sources of the water‑induced loads on a wastewaterpipe is developed in a systematic, stepwise manner bycombining experimental data with a numerical model. Bothexperimental and numerical configurations comply withEN 14366-1:2023 [1], with the vibration response quantifiedby the blocked forces at the wall fixing points. The turbulentflow is represented by a linear function of frequency indouble logarithmic scale, whereas the water impact at thebasement bend is modelled by a Gaussian‑shaped function.The parameters of PSD are identified by minimizing thedifference between measured and simulated blockedforces. The quantified excitation terms are incorporatedinto the numerical models, and the simulated blockedforces are compared with the measurements. The overallagreement is satisfactory and supports the applicability ofthe proposed method for predicting structure‑borne noisefrom wastewater systems.