Accounting for Planned Fuel Expulsion by Hybrid Rockets
Bibliographic record
Abstract
In order to maintain fuel structural integrity in multiple port hybrid rocket motors, there is generally more fuel between the ports than the motor would burn. A historical example of this design decision can be seen in the HPDP 250K Motor 2, which after testing the full 80 second duration, still had over an inch of fuel between each of its seven quadrilateral ports. The extra fuel between the ports produces a large fuel residual for the rocket, this fuel residual needs to be reduced in order to make hybrid motors more competitive. A new analysis technique was developed to reduce the amount of fuel between the ports, and take into account the inevitable expulsion of the fuel when it fails structurally. This technique involves structural analysis of the fuel grain to determine its critical failure modes. The technique also involves updating the ballistic analysis of the fuel grain as the fuel is being expulsed from the grain. Several 10 inch hybrid motors that used HTPB and liquid oxygen were fired at the SSC E-3 complex, and were used as the test bed and validation for this technique. The purpose of this paper is to demonstrate how to use this technique to plan for fuel expulsion, and take into account the performance changes of the rocket that this expulsion produces.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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 | 0.001 | 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".