Corey Weaver

Spray Characterization in a DISI Engine During Cold Start: (2) PDPA Investigation

Spray angle and penetration length data were taken under cold start conditions for a Direct Injection Spark Ignition engine to investigate the effect of transient conditions on spray development. The results show that during cold start, spray development depends primarily on fuel pressure, followed by Manifold Absolute Pressure (MAP). Injection frequency had little effect on spray development. The spray for this single hole, pressure-swirl fuel injector was characterized using high speed imaging. The fuel spray was characterized by three different regimes. Regime 1 comprised fuel pressures from 6 ? 13 bar, MAPs from 0.7 ? 1 bar, and was characterized by a large pre-spray along with large drop sizes. The spray angle and penetration lengths were comparatively small. Regime 2 comprised fuel pressures from 30 ? 39 bar and MAPs from 0.51 ? 0.54 bar. A large pre-spray and large drop sizes were still present but reduced compared to Regime 1. The spray angle and penetration lengths were typically larger then in Regime 1. Regime 3 comprised fuel pressures from 65 ? 102 bar and MAPs from 0.36 ? 0.46 bar. The fuel spray had a fully developed hollow cone structure with recirculation vortices at the edges of the spray, which constricted the spray angle. The spray angle was similar to Regime 2, while the penetration length increased. The pre-spray and drop size were reduced compared to Regime 2. In all regimes, decreasing MAP enlarged the spray angle, while injection frequency was not a significant factor.

Dynamometer Development of a Lightly Stratified Direct Injection Combustion System

This paper describes the dynamometer development of a lightly stratified direct-injection spark-ignition engine. The engine was designed for stratified charge operation at speeds and loads below 2000 RPM, 2 bar BMEP. Test results detailed in this report include evaluation of part-load stratified-charge, part-load homogeneous-charge, and WOT operation. The program had aggressive goals in improving WOT performance and part-load fuel consumption compared to a baseline PFI engine while meeting Stage V emissions levels. Mini-map analysis of the engine data indicated that the engine was able to meet the emissions and fuel consumption goals.

PLIF measurements of fuel distribution in a PFI engine under cold start conditions

This paper summarizes the first phase of an experimental effort focused on developing a comprehensive understanding of the in-cylinder air/fuel mixing and combustion processes in spark-ignition engines using laser-based fuel distribution and combustion measurements. As part of this first phase, a semi-quantitative, laser-induced fluorescence, fuel distribution measurement technique was developed and demonstrated. The calibration, correction, and image analysis processes associated with the technique were shown to be comparatively simple and effective (relative to other analytical and empirical methods). The error associated with the technique was shown to be 5 - 10 % under vapor phase conditions. This work was applied to a port fuel injected optical engine, which was designed for optical access through the piston and cylinder liner under firing conditions. The engine was operated under Coordinated Strategy for Starting with Reduced Emissions (CSSRE) operating conditions and characterized using the laser-induced fluorescence technique, as well as cylinder pressure analysis. Various ignition timings, Charge Motion Control Device (CMCD) positions, and fuel preparations were examined. Significant differences in fuel distributions were observed during the intake stroke for the various operating conditions, including differences in fuel droplet and vapor distribution. However, by the end of the compression stroke, it was difficult to discern between the fuel distributions for the various operating conditions, suggesting that all achieved approximately the same level of homogeneity. These results were supported by the cylinder pressure analysis which illustrated that the standard deviation in NMEP was explained completely by the effect of combustion phasing.

Ford’s New 3.5 l V6 Gasoline Engine

Ford banded a new motor technology as “EcoBoost”. It applies direct fuel injection and turbocharging to gasoline engines and provides a major improvement in fuel economy via engine downsizing, combined with improved performance. The first Ford engine with this technology is the 3.5 l V6 EcoBoost in the 2010 Lincoln MKS luxury sedan. Combustion, fuel, boost, and power conversion systems are discussed in detail with emphasis on the efficiency and value of these systems. Engine level fuel economy and performance are discussed, and compared to conventional gasoline engines.

Der neue 3,5-l-V6-Ottomotor von Ford

Die von Ford unter dem Namen „EcoBoost“ kunftig vermarktete Ottomotorentechnik kombiniert Direkt ein spritzung und Turboaufladung. Sie reduziert den Kraftstoffverbrauch durch Motor-downsizing bei gleichzeitig verbesserten Fahrleistungen. Der erste Ford-Motor mit dieser Technik ist der 3,5-l-V6-EcoBoost-Ottomotor in der Lincoln-MkS-Limousine, die 2009 in Serie geht. Ford bewertet die entsprechenden Entwicklungen an Verbrennungs-, Kraftstoff- und Aufladesystemen sowie am Kurbeltrieb mit Fokus auf Effizienz, Kosten und Nutzen. Kraftstoffverbrauch und Leistung werden vorgestellt und mit konventionellen Motoren verglichen.