Abstract
We use a conical bead pile to study the critical behavior of avalanches in granular matter. Velocity measurements for 292 videos of avalanches in the H2I000BE run were obtained using particle image velocimetry (PIV). A new method of analysis using PIV velocity measurements was introduced to analyze the pile in regions and develop methods for categorizing avalanches. We divide the surface of the pile into regions under two pile division regimes: quadrants and rings. Analysis of the whole surface of the pile shows that avalanche duration, total distance moved by beads, avalanche speed, and the active fraction of the pile are all correlated with avalanche size, with all respectively showing an increase as avalanche size increases, in agreement with expectation. The probability distribution of avalanche size P(s) for the H2I000BE run was shown to be consistent with the previous research and the predictions of mean field theory, where P(s) ∼ s−τ and universal exponent τ was found to be ∼ 1.5. We propose simple categories for avalanches according to their size and number of active regions on the pile. Quadrant region analysis shows that avalanches with an average size of 43 ± 4 beads are localized to one quadrant while those with an average size of 382 ± 25 are non-localized and active in all quadrants. There does not seem to be a pattern or cycle to the most active quadrant in time, but recording all avalanches regardless of size may confirm this finding. Ring region analysis shows that the active fraction in rings is correlated with avalanche size and that most avalanches occur in the middle and top rings of the pile. We observe that ∼ 60% of recorded avalanches have the majority of their activity on the left half of the pile, indicating a possible bias in small pile regions or a physical imbalance in the bead pile apparatus. Additional research into active region thresholds may aid in more accurate avalanche categorization.
Advisor
Lehman, Susan
Department
Physics
Recommended Citation
Buttler, Karmellah R., "Analyzing Avalanche Dynamics in a Conical Bead Pile with Particle Image Velocimetry" (2025). Senior Independent Study Theses. Paper 11363.
https://openworks.wooster.edu/independentstudy/11363
Disciplines
Physics
Keywords
critical behavior, granular matter, particle image velocimetry
Publication Date
2025
Degree Granted
Bachelor of Arts
Document Type
Senior Independent Study Thesis
© Copyright 2025 Karmellah R. Buttler