Non Equlibrium chemistry for hypersonic flows using an edge-based finite element method
Bibliographic record
Abstract
The development of hypersonic vehicles for civilian transport presents several multidisciplinary design challenges.The highly energetic conditions in the flow field can lead to chemical and thermal non-equilibrium effects that render complex the estimation of aerothermodynamic quantities such as lift, drag, mechanical stresses and heat fluxes through the body.These calculations are essential for the aerodynamic design of the vehicle as well as the development of thermal protection systems.Thus, there is a need for advanced computational tools to assist in the preliminary design phase.The present work extends the capabilities of the HALO3D simulation software into the non-equilibrium regime.The numerical approach enables accurate and robust computation of hypersonic flows, as well as relatively straightforward coupling with additional physical models.The physical and numerical modeling of several aspects related to chemical non-equilibrium are discussed.The species transport equations are solved in a loosely-coupled manner to reduce computational cost and simplify implementation.Reactions are modeled using laminar finite-rate chemistry, and various vibration-dissociation coupling models account for the effect of thermal non-equilibrium in the chemistry.Varying mixture composition is accounted for in all thermodynamic relations and several mixture transport property models are implemented.All calculations are encapsulated in an edge-based finite element framework that simultaneously incorporates many of the advantages of finite volume and finite element methods.A methodical verification and validation is carried out to isolate the effects and mechanisms in the model.The chemical source term and vibration-dissociation coupling models are first verified through unsteady reactor cases, then the mass diffusion is verified using a mixing layer problem.Subsequently, two-dimensional and three-dimensional flows in thermochemical non-equilibrium are simulated and comparisons are made against established codes and experimental data.Overall, the solver is shown to be extremely capable and promising for future hypersonics research.I would like to acknowledge the individuals who were instrumental in helping me conduct my research and bring this thesis to its present level.First and foremost, my deepest
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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 | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| 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 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".