Numerical simulation analysis of the effect of propane nozzle cutting oxygen orifice structure on the flow characteristics of cutting oxygen
Bibliographic record
Abstract
The cutting quality and capacity of an oxygen-propane flame cutting nozzle mainly depend on the characteristics of the cutting oxygen jet. In this paper, the structures of the cutting oxygen orifice of straight cylinder type, conical type, and arc type were investigated. Through theoretical calculations, numerical simulations, and experimental studies, the influence of the cutting oxygen orifice structure on the flow characteristics of the cutting oxygen flow, such as Mach number, velocity distribution, pressure distribution, and density distribution, was revealed. The results show that the straight cylinder type is a subsonic orifice with a maximum Mach number of 1 in jet, and the convergent-divergent (CD) type, namely Laval type, is a transonic orifice that allows the jet to cross from subsonic to supersonic velocities. Compared with a conical type orifice, an arc type orifice has better jet stability, a longer supersonic section, and smaller radial jet fluctuation at the outlet, which is conducive to slag blowing off during the cutting process to obtain better cutting surface quality. Finally, the numerical simulation results are validated through the use of 3D printing techniques and schlieren experiments.
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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 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".