Effects of Grain Geometry and Vibration on the Suppression of Combustion Instability in a Solid Rocket Motor
Bibliographic record
Abstract
A comprehensive numerical model for internal ballistic simulation under dynamic flow, combustion and structural vibration conditions is used to investigate the effectiveness of grain port area transitions of a reference solid rocket motor as a means for suppression of axial combustion instability symptoms. Modification of the propellant grain geometry is one of several traditional means for suppressing symptoms in actual motors. With respect to these symptoms, individual transient simulation runs show the evolution of the axial pressure wave and associated DC shift for the given grain geometry, as initiated by a given pressure disturbance. Limit pressure wave magnitudes are collected for a number of simulation runs for different grain area transition positions, steepness and aspect ratios, and mapped on an attenuation trend chart. Effects of acceleration, through structural vibration of the propellant surface, on the combustion process are investigated, and their influence on the effectiveness of grain area transitions is examined. With or without acceleration/vibrations effects included, the numerical results produced in this study confirm the significant ability of a grain area transition to suppress combustion instability symptoms.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".