Simulation of Flow within Armour Blocks in a Breakwater

This paper provides some results of a new procedure to analyze the hydrodynamic aspects of the interactions between maritime emerged breakwaters and waves by integrating computer-aided design and computational fluid dynamicsCFD. The structure is modeled in the numerical domain by overlapping individual three-dimensional elements (Xbloc*), very much like the real world or physical laboratory testing.

A computational grid is fitted fine enough to provide enough computational nodes within the flow paths. Flow of the fluid within the interstices among concrete blocks is evaluated by integrating the Reynolds averaged Navier—Stokes equations inside the voids instead of using the "porous media" approach.

The aim is to investigate the reliability of this approach as a design tool. Therefore, for the results' validation, the numerical run-up and reflection effects on virtual breakwater (armour in Xbloc, toe protection, and filter layer in stones) were compared with some empirical formulas and some similar laboratory tests.

Obviously, the presented model can be supportive to the physical modeling, comparing multiple preliminary design solutions, and providing guidance on the optimal choice to be subjected to subsequent laboratory tests. Here are presented the results of a first simple validation procedure. The validation shows that, at present, this innovative approach can be used in the breakwater design phase for comparison between several design solutions with a significant minor cost.