  Hard particle erosion and cavitation damage are two main wear problems that
can affect the internal components of hydraulic machinery such as hydraulic
turbines or pumps. If both problems synergistically act together, the damage
can be more severe and result in high maintenance costs. In this work, a study
of the interaction of hard particles and cavitation bubbles is developed to
understand their interactive behavior. Experimental tests and numerical
simulations using computational fluid dynamics (CFD) were performed.
Experimentally, a cavitation bubble was generated with an electric spark near a
solid surface, and its interaction with hard particles of different sizes and
materials was observed using a high-speed camera. A simplified analytical
approach was developed to model the behavior of the particles near the bubble
interface during its collapse. Computationally, we simulated an air bubble that
grew and collapsed near a solid wall while interacting with one particle near
the bubble interface. Several simulations with different conditions were made
and validated with the experimental data. The experimental data obtained from
particles above the bubble were consistent with the numerical results and
analytical study. The particle size, density and position of the particle with
respect to the bubble interface strongly affected the maximum velocity of the
particles.
