Experimental Investigation on the Influence of Boost on Emissions and Combustion in an SGDI-Engine Operated in Stratified Mode
Bibliographic record
Abstract
<div class="section abstract"><div class="htmlview paragraph">Among many techniques used for increasing fuel efficiency of a modern Gasoline Direct-Injected (GDI) engine are boosting and stratified operation. In modern downsized GDI engines, boosting is standard in order to achieve a high power output. Boosted GDI-engines have however mostly been operated in homogenous mode and little is known on the effects of operating a boosted GDI-engine in stratified mode.</div><div class="htmlview paragraph">This paper presents the influence on combustion, standard emissions and particulate size distribution in a Spray-Guided, Gasoline, Direct-Injected (SGDI), single cylinder, research engine operated with various levels of boost.</div><div class="htmlview paragraph">The engine was operated in steady state mode at five engine operating points of various load and speed. The engine was boosted with a Roots blower and operated at four levels of boost as well as atmospheric pressure for comparison. The engine was fueled with market gasoline (95 RON) blended with 10% ethanol. The gas motion induced by the engine head was primarily tumble motion but a small amount of swirl. The spark plug and injector was mounted in parallel with the intake valves.</div><div class="htmlview paragraph">Results indicate that exhaust temperature and NOx emissions decrease with increasing boost. Hydrocarbon emissions increase with increasing boost. The results on particulate emissions indicate that nucleation mode particulates increase with increasing boost. The opposite trend was observed for agglomeration mode particulates which decreased with increasing boost pressure.</div></div>
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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".