Numerical simulation results show velocity field distribution of the fluid flows and corresponding streamlines (a) in the presence and (b) in the absence of a cavitation bubble. Red (dark blue) denotes the highest (lowest) flow speeds. The cavitation bubble is depicted by the white circle located at the centre of the computational area. The effect of the laser pulses is modelled as a boundary heat source at the lower right quarter of the bubble. A porous medium was introduced to model the aggregate positioned adjacent to the lower-right quarter of the bubble. In the absence of a bubble, we described the aggregate, also as a porous medium, located at the centre of the computational area (black circle). The beam profile of the laser is Gaussian, so we introduced a heat source with a Gaussian temperature profile to represent the effect of the laser. This source was located at the centre of the aggregate. The diameters of the porous medium and the laser beam were chosen to be 15 µm and 8 µm. The streamlines can be seen to penetrate the aggregate because it is modelled as a porous medium.