Transient evolution of flow profiles in a shear banding wormlike micellar solution: experimental results and a comparison with the VCM model
Bibliographic record
Abstract
In this paper we investigate the flow of a shear banding wormlike micellar fluid based on cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal). The flow is studied in a custom-built Taylor-Couette (TC) cell via a combination of particle tracking velocimetry and in situ rheology. The spatiotemporal evolution of the velocity profile across the rheometer gap is tracked after an imposed step in the shear rate. In a range of shear rates the mixture shows shear banding behavior, that is distinct and differing shear rate profiles across the gap. As the shear bands form temporally, an elastic recoil including negative velocity (that is in the opposite direction to that of the imposed motion) is observed in a subset of the gap. While elastic recoil has been reported in experiments on monodisperse polymers [S. Ravindranath, et al., Macromolecules, 2008, 41, 2663-2670], on a wormlike micellar solution in a cone-plate rheometer [P. E. Boukany and S. Q. Wang, Macromolecules, 2008, 41(4), 1455-1464], and in theoretical studies [L. Zhou, et al., J. Non-Newtonian Fluid Mech., 2014, 211, 70-83; J. M. Adams, et al., J. Rheol., 2011, 55, 1007-1032] of wormlike micellar flows, it has not been previously reported in experiments on shear banding wormlike micelles in Taylor-Couette flows. Additionally, the mixture shows significant wall slip at the outer (stationary) Couette cylinder at high shear rates. Experimental results are compared to simulations of models of wormlike micelles, particularly the VCM model [L. Zhou, et al., J. Non-Newtonian Fluid Mech., 2014, 211, 70-83]. There are differences between the experimental results for this fluid and those reported previously. The difference arises from the size of the elasticity number which for the fluid reported in the paper is four orders of magnitude larger than that of other preparations.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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".