What the study found
Vertical vibrations changed how a lunar regolith simulant moved through a hopper, which is a container that releases bulk material through an opening. The study found that vibrations made flow more regular and reduced clogging, but the average mass flow rate stayed lower than in purely gravitational flow.
Why the authors say this matters
The authors say hoppers are expected to be important for handling lunar regolith in future lunar exploration missions, from collection and storage to in situ resource utilization, meaning using local materials on the Moon. The study suggests that understanding vibration effects may help explain and manage regolith discharge behavior in such systems.
What the researchers tested
The researchers carried out a parametric experimental investigation using the LHS-1 regolith simulant. They varied vibration conditions and observed discharge dynamics from the hopper orifice, including mass flow rate, material displacement patterns, and jamming or arching behavior.
What worked and what didn't
Vibrations reduced the probability of arching, which is when grains form a stable blockage across the opening, and made the flow more spatially uniform. Four flow configurations were identified: funnel, mass, asymmetric, and ratholing; funnel flow was most common, while asymmetric and ratholing appeared only at relatively high shaking frequency and amplitude. Low frequencies promoted arching, and high frequencies could also lead to clogging again at some thresholds, especially at low acceleration amplitude.
What to keep in mind
The abstract does not describe the size of the experimental sample, measurement uncertainty, or how broadly the results generalize beyond the LHS-1 simulant and the tested hopper conditions. It also notes that increasing vibration amplitude becomes less effective as sample mass grows, suggesting other factors such as gravity-induced compaction and particle rearrangement may influence the results.
Key points
- Vertical vibrations made hopper discharge of lunar regolith simulant more regular and spatially uniform.
- The average mass flow rate under vibration was consistently lower than in gravity-only flow.
- Vibrations reduced the probability of arching and other clogging events.
- Four flow regimes were identified: funnel, mass, asymmetric, and ratholing.
- Low frequencies promoted arching, while some high-frequency conditions also allowed clogging to reappear.
Disclosure
- Research title:
- Vibrations change lunar regolith flow in hopper discharge
- Authors:
- Marcello Lappa, Peter Watson, S. Vincent-Bonnieu
- Institutions:
- European Space Agency, European Space Research and Technology Centre, University of Strathclyde, University of Strathclyde
- Publication date:
- 2026-04-21
- DOI:
- 10.1122/8.0001055
- OpenAlex record:
- View
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