SPH modeling of rapid multiphase flows and shock wave propagation

This work shows an application of the Smoothed Particle Hydrodynamics (SPH) for the numerical modeling of engineering problems involving rapid evolution over time, high strain and gradients, heterogeneity, deformable contours and the presence of mobile material interfaces. Following a Lagrangian approach the continuum is discretized by means of a finite number of material particles carrying physical properties and moving according to Newton’s equations of the classical physics. Spatial derivatives of a variable at a point are approximated by using the information on the neighboring particles based on the kernel approximation. This paper recalls the basics of the method along with some numerical aspects concerning boundaries treatment, time integration scheme etc.; furthermore some details are provided about the recent improvements carried out for SPH simulations of: a) non-cohesive sediment flushing by rapid water discharge in an hydropower reservoir, b) underwater explosion for bottom sediment resuspension in an artificial reservoir. Numerical examples are illustrated and discussed concerning 2D and 3D test cases carried out with the aim of investigating the basic features of both sediment dynamics and gas explosion: obtained results shows that the SPH method can be applied to model the relevant engineering aspects of the considered problems and can be a helpful tool for future design applications in the field of hydropower reservoir management.