Microgravitational Particle Interaction in Monochromatic High-Frequency Oscillatory Flow *

Particle-resolved Direct Numerical Simulations (pr-DNS) are performed to investigate the interaction of two spherical particles submerged in a viscous fluid and subjected to a monochromatic high-frequency oscillatory flow in the absence of gravity. This fundamental research serves the main objective of studying the flocculation behavior of clay suspensions in a microgravity environment. The numerical setup is based on experiments previously conducted by the same authors onboard the International Space Station (ISS). The applied range of frequencies corresponds to onboard vibrations (g-jitter) caused by equipment operations and routine crew activity. The simulations account for the fluid-particle interaction via the Immersed Boundary Method (IBM) by resolving the flow field around the suspended particles. In this talk, we will present a detailed sensitivity analysis of the relevant parameters leading to attractive or repulsive interactions between two particles. First results show that the data collapses using an appropriate non-dimensional number reflecting the relevant physical effects of inertia, viscous, and pressure forces.