Stability of Boundary Layers over Porous Walls with Suction
Bibliographic record
Abstract
Although there is considerable interest in using wall suction to increase boundary-layer stability, stability analyses suggest that porous walls are inherently destabilizing. We explore this contradiction by performing a spatial linear stability analysis of the asymptotic suction boundary layer using a realistic model of wall suction. The porous wall is modelled as a layer of rigid, homogeneous, isotropic, porous material of small permeability, in which inertial effects may be neglected. The porous layer is bounded above by a semi-infinite region in which a boundary layer is driven by a constant freestream velocity. The wall suction is created by applying a suction pressure to a semi-infinite region below the porous layer. Our stability analysis takes account of the full coupling between the flowfields in the boundary-layer and suction regions, governed by the Navier–Stokes equations, and the flow in the porous layer, governed by the volume-averaged Navier–Stokes equations. We find that small amounts of wall permeability destabilize the Tollmien–Schlichting wave and cause a substantial broadening of the unstable region. As a result, the stabilization of boundary layers by wall suction is substantially less effective and more expensive than what is predicted by classical boundary-layer theory.
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 | 0.000 | 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".