A Comparative Study of Laminar-Turbulent Displacement in Eccentric Annulus Under Imposed Flow Rate Conditions
Bibliographic record
Abstract
Abstract In this paper, we present and discuss an experimental study of fluid-fluid displacement in a fully eccentric horizontal annulus. Experiments were designed to simulate turbulent displacing flows, and the results are used to investigate the displacement processes in terms of interface dynamics and displacement efficiency. It is widely believed that turbulent flows are more efficient at displacement, but it is not always clear under what conditions this comparison is made. A set of experiments was conducted to investigate the role of flow regime under a constant imposed flow rate in the absence of any stabilizing buoyancy effect (i.e. iso-density fluids). Carbopol solutions are displaced with various concentrations of Xanthan gum, to simulate a drilling mud displaced by a spacer fluid. The flow regime of the displacing fluid spans from laminar to fully turbulent flow regimes. The displacement tests are all unsteady in a sense that wide-gap velocity is always faster than that of the narrow-gap. The displacement flows and interface dynamics are captured using optical techniques, and the images are post-processed to ascertain the displacement efficiency, interface velocity and elongation. We conclude with a discussion on the significance of outcomes achieved in this study, and also limitations of the experimental technique.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".