Immersed boundary method and centered scheme for the study of aero-acoustic field in SRMs
Bibliographic record
Abstract
A monolithic aft-finocyl Solid Rocket Motor is characterized by a propellant grain with a cylindrical core and a final star-shaped region located close to the thrust nozzle. This peculiar geometry of the pro- pellant grain can induce significant effects on the combustion chamber pressure field that can exhibit an unsteady behavior for some typical time windows of the operative life of the motor. At the present state of the art, the coupling of hydrodynamic instabilities and chamber acoustics is supposed to be the main responsible of pressure oscillations onset. The paper aims to investigate the possibility to study the aeroa- coustic problem in aft-finocyl SRMs by means of 3D unsteady CFD simulations performed by using a new 2 nd hybrid self-adjusting centered scheme. An immersed boundary method is employed for the boundary treatment. The new numerical method, along with the immersed boundary technique, is validated by sim- ulating a Taylor-Culick flow and a Laval nozzle. Then the numerical method is applied to a simplified aft-finocyl solid rocket motor showing the capability of the code to characterize pressure oscillations at limit cycle conditions.
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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".