Particle resuspension in environmental flows

Particle resuspension in environmental flows

Motivations

Understanding the mechanism of particle resuspension by turbulent flow from a sediment bed is crucial in many natural and industrial flows. In riverine environments, the resuspension of microplastic greatly increases during rain events. This project aims to understand the micromechanical behavior of particle resuspension through experimental and numerical approaches. A closed-loop channel facility will be used to study the mobilization of millimeter-sized polymer particles from a sediment bed composed of equal diameter glass beads.

In-situ and high-speed visualization of particle detachment

Initial experiments will be performed with a high-speed camera, and the process of resuspension of plastic particles, as illustrated in Figure 1, will be compared with studies of monolayer and multiple layers performed for single-density particles. With the ultrafast X-ray computed tomography system (ROFEX), the three-dimensional opaque sediment bed can be scanned. This will allow us to identify and map the entrapped plastic particles for different time and flow conditions. Furthermore, the ROFEX will record individual particles crossing two measurement planes at 1000 samples per second. This system will enable the measurement of plastic and glass particle velocity distribution in both the sediment bed and suspended in the flow.

In addition to the experimental study, Direct Numerical Simulations (DNS) with grain-level resolution will complement the investigation of the particle resuspension. Idealized experimental conditions will be simulated to provide greater detail into hydrodynamic forces acting on particle-fluid interactions. Additionally, DNS allows for the investigation of a broader range of particle and flow parameters, including complex conditions that are challenging to replicate experimentally. Through this combined experimental and numerical approach, this project aims to enhance the understanding of particle resuspension mechanisms. The insights gained from this study can contribute to improving stochastic downscaling methods for large-scale marine and riverine simulations. These findings can be used to support marine mining operations, aid in controlling microplastic resuspension in riverine environments, and enhance the efficiency of dredging processes. The results will also find applications in the industry. Examples include the oil and gas production, water treatment, and mining.

Funding

This project is funded by a DRESDEN-concept (DDc) Research Group and is conducted in collaboration with the Technische Universität Dresden.

Publications

Höhn, R., Vowinckel, B., Lecrivain, G. (2025). Investigating microplastic resuspension in environmental flows: Experimental and numerical approaches. Poster presented at the EGU General Assembly 2025, 27 April – 2 May 2025.

Banari, A., Graebe, K., Rudolph, M., Mohseni, E., Lorenz, P., Zimmer, K., Hübner, R., Henry, C., Bossy, M., Hampel, U., Lecrivain, G. (2023). Influence of engineered roughness microstructures on adhesion and turbulent resuspension of microparticles. Journal of Aerosol Science, 174, 106258.