Investigation of Unsteady Pressure Fluctuations in Flow over Backward-Facing Step
Bibliographic record
Abstract
Flow over a backward-facing step at , based on the step height, is simulated using the Divergence Free Synthetic Eddy Method of Poletto et al. (“A New Divergence Free Synthetic Eddy Method for the Reproduction of Inlet Flow Conditions for LES,” Flow, Turbulence and Combustion, Vol. 91, No. 3, 2013, pp. 519–539.), implemented in OpenFOAM® 1606, which preserves the instantaneous fluctuating pressure field in the domain, which is normally lost. Examination of the pressure spectra at various positions normal to the wall is well represented by wall-pressure measurements at all but the highest frequencies examined here. Various spectral peaks corresponding to shear-layer movement, discrete vortex shedding from the step, and numerous shear-layer instabilities are investigated using power and cross-spectral measurements of the fluctuating wall pressures. Convective velocities obtained from the cross-spectral phase indicate that the lowest frequencies convect slowly, whereas the higher frequencies near the measured spectral peaks convect at . There is an increase in convective velocity as the measurement locations are moved farther downstream. Additionally, an increase in peak frequency was found in this examination; however, the increase in convective velocity (approximately equal to 33%) and frequency (approximately equal to 7–11%) calculated at different streamwise positions were not found to be directly proportional, indicating that the increase in peak frequency cannot be solely explained by flow acceleration but that the structures are likely undergoing streamwise or spanwise deformation as well.
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".