Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
2 results
Search Results
Article Citation - WoS: 15Citation - Scopus: 15Predicting the Effects of Direct-Injected Fuels Co-Powered by High-CO2 Biogas on RCCI Engine Emissions Using Kinetic Mechanisms and Multi-Objective Optimization(Elsevier, 2024-04) Dalha, Ibrahim B.; Koca, Kemal; Said, Mior A.; Rafindadi, Aminu D.High inert gas content in biogas resulted in poor burning and emissions attributes, though scarcely investigated in reactivity controlled compression ignition (RCCI). Established kinetic mechanisms were combined with multiobjective optimization to investigate, predict, and analyze emissions occurrence and trade-offs for reduced environmental impacts. The work examined the impact of direct-injected high reactivity fuels (HRF) and portinjected Biogas at various inert gas (carbon dioxide, CO2) rates (25 - 45% vol), biogas fractions (40 - 70%), speeds (1600 - 2000 rpm), and loads (4.5 - 6.5 bar IMEP) on emissions of RCCI engine, experimentally. The findings revealed that while engine speeds greatly decreased CO (carbon monoxide) and NOx (nitrate oxide) emissions with rising unburned hydrocarbon (UHC) regardless of HRF employed, higher engine load significantly reduced UHC emissions. Diesel-biogas reduces NOx emissions and performs better in reducing CO and UHC emissions at lower speeds than B5-biogas, except in low-level loads. Although increasing CO2 impact led to a reduction in UHC and CO emissions, the biogas proportion was the most significant variable. The main factor influencing increased NOx emissions was engine load, which is inversely correlated with reduced NOx and increased particulate emissions owing to high CO2 content and biogas proportion. The premixed mode's optimisation outcome confirms the trade -off reduction at 5.5 bar IMEP, 35.586% CO2, and 50% fraction. As a result, running the RCCI engine with direct-injected diesel co-powered in equal proportion with high-CO2 biogas cuts the emissions trade -off dramatically, limiting the environmental repercussions of the emissions.Article Citation - WoS: 1Citation - Scopus: 1Investigating the Tradeoff Between the MMF Distortion and End Turn Length of a 2-Pole Line Start SynRM Performance(Springer int Publ Ag, 2023-07-19) Tekgun, Didem; Cosdu, Muhammed M.; Tekgun, Burak; Alan, IrfanConventional 2-pole AC machine windings have long end windings and generate harmonics, which increase losses and reduce torque density. This study investigates the performance tradeoff between the level of distortion (THD) in winding magneto-motive force (MMF) and end turn length on a 2-pole line start Synchronous Reluctance Machine (LS-SynRM) machine. A two-stage approach is used, winding and geometry optimization. Various multilayer winding configurations having unevenly distributed number of turns are investigated. First, the percentage of the turns in a coil group is optimized for minimum harmonics and end turn length for all structures. Second, geometric optimization is performed on selected winding configurations. Sixteen different configurations are optimized, and Pareto optimal solutions are obtained. Later, these solutions are graded with a new score-based assessment method to quantify the quality of the results. It is concluded that the designs having lower THD in winding MMF perform better than the designs with shorter end turns in terms of efficiency and torque density.