This paper deals with the numerical prediction of noise from a marine propeller in presence of a sheet cavitation. The analysis is performed by coupling an acoustic code based on the Ffowcs Williams-Hawkings (FWH) equation to a Boundary Element Method (BEM), able to simulate the appearance and the time evolution of a bubble on the blade surface. The noise signature is determined by using a modified version of the well-known Farassat solving formulation 1A, where the integration domain is time-dependent and corresponds to the blade surface plus the bubble. The results reveal the expected true monopole nature of the body-source, characterized by a significant increase of the noise level and the occurrence of an impulsive waveform (with a higher frequency content) of the acoustic pressure.
Sheet cavitation noise prediction from a marine propeller
Ianniello S
2015
Abstract
This paper deals with the numerical prediction of noise from a marine propeller in presence of a sheet cavitation. The analysis is performed by coupling an acoustic code based on the Ffowcs Williams-Hawkings (FWH) equation to a Boundary Element Method (BEM), able to simulate the appearance and the time evolution of a bubble on the blade surface. The noise signature is determined by using a modified version of the well-known Farassat solving formulation 1A, where the integration domain is time-dependent and corresponds to the blade surface plus the bubble. The results reveal the expected true monopole nature of the body-source, characterized by a significant increase of the noise level and the occurrence of an impulsive waveform (with a higher frequency content) of the acoustic pressure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


