Study on Calculation Method of Negative Pressure Loss Considering the Deformation of Drainage Borehole
Bibliographic record
Abstract
The experimental system for borehole negative pressure distribution and flow distribution was constructed. The laws of borehole negative pressure distribution and flow distribution under different negative pressure conditions with consideration of borehole deformation were obtained. The theory of calculating borehole negative pressure loss was analyzed. A negative pressure loss calculation method with consideration of borehole deformation was proposed based on experimental measured results, and its validity was verified comparing the results calculated by proposed method and experimental measured results. Results show that: 1) The negative pressure loss for complete hole is relatively small, the negative pressures at different parts of borehole are similar with each other, and the borehole extraction flow is approximately in a linear distribution along borehole length direction. The larger the orifice pressure is, the larger the borehole extraction flow is, and the larger the borehole negative pressure loss is (it is worth noting that borehole negative pressure is still much smaller than orifice pressure). 2) In the case of hole-bottom collapse, the negative pressure loss in the collapse section is larger than that in complete section. Since the flow in the collapse section is small, its negative pressure loss is small as well. The total negative pressure loss upon hole collapse is larger than that in complete hole, while its total extraction flow is slightly smaller than that of complete hole. The hole-bottom collapse does not significantly affect the gas extraction performance. 3) The negative pressure loss results, which is calculated by the proposed method based on the consideration of borehole deformation, are consistent with the experiment results. Therefore, the proposed method can be used to calculate the negative pressure loss of extraction borehole.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".