Integrated experimental investigation of combustion-chamber geometry, injection pressure, and oxygenated gasoline blends in a gasoline direct-injection engine
Journal of Thermal Analysis and Calorimetry, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10973-026-16310-9
- Dergi Adı: Journal of Thermal Analysis and Calorimetry
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Chimica, Compendex, Index Islamicus, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Gasoline direct injection, Combustion chamber geometry, Wall-Guided Combustion, Injection Pressure Optimization, Oxygenated Fuel Blends
- Uşak Üniversitesi Adresli: Evet
Özet
The coupled effects of combustion-chamber geometry, fuel injection pressure, and oxygenated gasoline blending on mixture preparation, combustion, performance, and emissions were experimentally investigated in a modified single-cylinder gasoline direct-injection (GDI) engine. Three mixture-formation configurations, namely wall-guided (WG), spray-guided (SG), and air-guided (AG) combustion, were evaluated under identical base-engine conditions at 1500 rpm and a compression ratio of 10:1. Fuel injection pressures of 100, 150, and 200 bar were examined, followed by evaluation of gasoline blends containing 20–60% methanol, ethanol, or n-butanol at the selected high-pressure operating condition. Engine performance was assessed using brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), while combustion was characterized through crank-angle-resolved in-cylinder pressure and apparent heat release rate (HRR). Carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), and soot emissions were simultaneously evaluated to establish the performance–emission trade-offs. Increasing injection pressure improved mixture preparation and combustion efficiency, with the 200 bar condition consistently outperforming 100 and 150 bar operation. Among the investigated chamber configurations, WG operation at 200 bar produced the highest BTE of 41.1% at 75% load and the minimum BSFC of 0.273 kgkW−1h−1. The same configuration reduced CO, HC, and soot relative to the less favorable geometry-pressure combinations, although the stronger combustion intensity resulted in a corresponding NOx penalty. Among the oxygenated fuels, B20 exhibited the closest performance to gasoline, with BTE of 36.42% and BSFC of 0.281 kgkW−1h−1 at 75% load. Its combustion characteristics also remained comparatively close to gasoline, with peak cylinder pressure of approximately 80.9–81.2 bar and peak HRR of approximately 73.51 J°C−1A−1, compared with 82.55 bar and 74.62 J°C−1A−1, respectively, for gasoline. In contrast, E20 provided the more favorable NOx–performance compromise, reducing NOx by approximately 12–15% while retaining acceptable efficiency. Higher ethanol and methanol fractions further reduced HC and soot, but their lower energy density and stronger evaporative cooling increased specific fuel consumption. The results demonstrate that chamber-guided mixture formation and injection pressure strongly interact with fuel thermophysical properties in determining GDI combustion behavior. Under the investigated steady-state conditions, WG operation at 200 bar provides the most favorable gasoline baseline, while moderate n-butanol and ethanol blending offers different pathways toward performance retention and emission reduction, respectively. The findings provide an experimentally based framework for jointly selecting combustion-chamber configuration, injection pressure, and oxygenated-fuel fraction in GDI engines.