Influence of irregular canyon shape on location of truncation surface

Fluid–structure interaction phenomenon, by its nature, is three-dimensional and consequently dependant on the shape of a dam and canyon that in-fact defines the spatial domain where the generated acoustic waves are spread. The complex topography of the terrain in general requires sufficiently large extent of reservoir to be included in the model, which is undoubtedly feasible if BEM technique is used. This paper shows that the irregular canyon shape dictates “the most adequate” location of the truncation surface that gives the smallest negative impact on calculation accuracy. The derived conclusions are based on various 3D analyses of a rigid dam–reservoir system with different shapes and lengths of the fluid domain, where the fluid is treated as incompressible and inviscid. The presented work contributes towards disclosure of the topographic site effects and towards promotion of simple and effective procedure for generation of BE mesh, which is quite accurate in following the topology of the terrain.