The Sensitivity Study of a Mechanical Loss Model in Turbocharger System
Bibliographic record
Abstract
Abstract 3D modelling can be a very useful tool for optimising the design of turbocharger turbines. However, it is difficult to achieve high levels of correlation with experimental data which can undermine confidence in the 3D model results. A key difference between modelling and experiments is the way turbine efficiency is estimated: in CFD this is estimated directly from the shaft torque created by the turbine, however in experiments this is usually estimated based on the enthalpy rise measured at the compressor. This means that there is an inherent offset between the two which is the mechanical losses of the bearing system used to support the connecting shaft. The accuracy of the mechanical loss estimate can therefore play a critical role in the correlation of 3D modelling with experiments. A 3D CFD model of a turbocharger turbine of a 1.5L gasoline engine has been coupled with a 0D mechanical losses model. The model comprises of seven parameters that characterise the bearing losses such as oil film thickness, bearing surface finish and clearances. A sensitivity study is conducted on these parameters to understand which are the critical aspects that should be parameterised and what relationship these parameters may have with the operating state of the turbocharger (shaft speed, shaft torque etc.). Experimental measurements were conducted for the same turbocharger to provide a baseline for assessing the impact of the mechanical losses model. These provide the boundary conditions to the CFD by ignoring the effects of heat transfer, and the results were compared to the 3D simulation results.
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".