| dc.description.abstract | Understanding the propagation of an acoustic wave through a region of bubbles has a number of applications in underwater acoustics including the analysis of bubble screen performance. Used to reduce the impact of high amplitude acoustic sources, bubble screens are used during offshore wind turbine installation and also have the potential to reduce noise from shipping. Computational modelling of acoustic wave propagation through a bubble screen is challenging due to the relatively high void fractions and the multiple interactions that take place between the incident acoustic wave and the bubbles. In this work, a multiphase approach is applied to this problem, where the Euler equations are solved numerically for both the liquid and gas phases, with a Lagrangian front-tracking technique to capture the interface. A series of simulations are conducted with different random distributions of bubbles and different void fractions, and the results show that a transmission coefficient of less than 0.01 can be achieved for a void fraction of 3%. It is also shown that the distribution of the bubbles plays a significant role in determining the transmission coefficient. For different spatial distributions of a fixed number of bubbles within a fixed area, the highest transmission coefficient is found to be 4 times higher than the lowest, highlighting the importance of properly accounting for the location of each bubble within the column. | en_US |
