Investigation of Baffled-Tube Ram Accelerator Configurations
Bibliographic record
Abstract
View Video Presentation: https://doi.org/10.2514/6.2023-2186.vid The ram accelerator is a combustion driven launch system designed to accelerate projectiles to hypersonic velocities. To improve performance and extend operability limits, the baffled tube ram accelerator (BTRA) was developed, utilizing a series of washer-like baffles with axisymmetric projectiles. This work presents the results from an experimental investigation on the influences of propellant chemistry, pressure staging, baffle configuration, and projectile geometries on thrust characteristics of the BTRA. Thrust was found to scale with heat release in a methane-air-diluent mixture, and to scale proportionally with tube fill pressure. Increased baffle chamber diameter was found to have a detrimental effect on thrust performance, while increased projectile length resulted in an increase in thrust at any given fill pressure. Continuous operation was demonstrated in an 8-m-long BTRA over the velocity range of 0.7 km/s to 1.4 km/s and Mach numbers of 2.0 to 4.2. The upper Mach number limit to BTRA operation has not yet been determined.
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 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 | 0.001 |
| 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 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".