Growth and static stability of bubble clouds in yield stress fluids
Bibliographic record
Abstract
This study explores the growth and static stability of bubble clouds in yield-stress fluids using an experimental approach. Carbopol gels with varying concentrations and initial gas contents as well as Laponite gels are used as model yield stress fluids in our experiments. A vacuum system is exploited to generate the bubbles and control their growth in the gels. The focus of this study is on determining the maximum gas concentration which could be held trapped in the system and the critical yield number, i.e. the ratio of the yield stress to the buoyancy stress at the onset of motion. Our findings demonstrate the effect of the bubbles proximity as well as the gel structure and rheology on both the maximum gas concentration and critical yield number. Our results confirm that for higher gas fractions, the critical yield number is larger. Also, they show that the size and degree of elongation of the bubbles at the onset of motion are controlled by their proximity as well as the gel rheology. Moreover, our results reveal two different scenarios for the bubble release depending on the uniformity of the structure of the gel. In the case of low concentration Carbopol gels, characterized by uniform structures, quasi mono-dispersed bubble suspensions are formed. At a pretty high gas concentration, this might lead to a bubble cloud burst upon static instability onset. Conversely, in the case of high concentration Carbopol gels or Laponite gels, the polydisperse bubble suspensions emerge and the bubble release occurs gradually rather than suddenly. It can be associated with the heterogeneous structure of these gels stemming from their significant shear history dependence.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".