Methods
Simulations were conducted as axisymmetric models (2D interface) in
COMSOL multiphysics 5.4. To find model dimensions, the sonication tubes
were dismantled, and height, thickness, and width were measured with
slide calipers. The model was then drawn directly in the COMSOL computer
aided design interface with specified acoustic and flow boundary
conditions (Fig 7, Table 1,2,3). The sonication tubes as well as tips
are cylindrical and can be represented by taking half of the cross
section along the mid plane (axisymmetric geometry). Finite element
analysis demands the simulation domain to be discretized to number of
elements, and the solution is obtained at each of the nodes.