Numerical simulation of the flow-induced noise of a ducted diaphragm using the Lattice Boltzmann Method

Acoustic discretion is of prime importance for submarines while operating, in order not to be detected. One of the submarine acoustic sources is the noise induced by water flows passing through singularities in pipes ending at the hull, thus radiating acoustic waves in the vessel surroundings. Predicting the noise induced by singularities in pipes is then fundamental to determine the acoustic signature of an underwater ship. Several Computational Aero-Acoustics methods have been implemented in order to predict the sound induced by singularities such as diaphragms and perforated plates. In this study, the Lattice Boltzmann Method (LBM) coupled to Large Eddy Simulation (LES) is used to simulate the flow passing through a diaphragm and to predict the induced noise. The method is first implemented for an airflow in a rectangular duct, with the final objective of being applied to confined water flows encountered in circular or rectangular ducts.