Heat transfer characteristics of heat exchanger elements in acoustic standing waves
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Thermoacoustic refrigerators use sound waves and the associated interactions between oscillatory gas particles and solid structures to transfer heat and generate cooling power. Heat exchangers are used to move the extracted heat from the periodic oscillatory flows. Heat transfer predictions based on steady state correlations are inaccurate for heat exchangers immersed in oscillating flows. The effects of flow oscillation on heat transfer characteristics related to vortex formation are not fully understood. The objective of the present study was to synchronously measure the flow velocity and the temperature fields and characterize the heat transfer from simplified heat exchanger geometries immersed in oscillatory flows typical of thermoacoustic systems. Thermal and flow fields in the near field of three simplified heat exchanger geometries were visualized utilizing a synchronized PIV and PLIF technique. These configurations were investigated: 1) single cylinder, 2) tandem cylinders, and 3) finned tube. For the single cylinder case, cylinders with two different diameters were investigated independently. The results confirmed the reproducibility of the experimental data. For the tandem cylinders case, two different center-to-center distance to diameter ratios were chosen to investigate the effects of cylinder spacing and hydrodynamic interference. For the finned tube study, two longitudinal fins were attached to either side of a cylinder in order to better mimic the conditions of a real heat exchanger. The present work was the first systematic study to characterize heat transfer from simplified heat exchanger geometries subjected to oscillatory flow. Post processing of the visualization images allowed the determination of local time-dependent, spatially-averaged, and total heat transfer rates as a function of acoustic Reynolds number, Keulegan-Carpenter number and dimensionless frequency parameter. The intermittent, time-varying vortex shedding behaviour of the flow caused a strong time dependence and a naturally unsteady heat transfer character. It was found that the vortex generation mechanism and heat transfer rates from bluff bodies immersed in oscillatory flows are totally different from those in steady state flows.
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.
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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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 it