Mixture Formation and Combustion in a Spark Ignition Engine with Direct Fuel Injection

1992 ◽  
Author(s):  
L. Spiegel ◽  
U. Spicher
Author(s):  
Edward Rakosi ◽  
Radu Rosca

The paper presents some experimental results regarding a stratified charge spark ignition engine. We have applied the divided combustion chamber concept, using a flame jet in order to ignite the fuel-air mixture. The fueling system was a combined one: the cylinder head combustion chamber (secondary, auxiliary) was fueled by direct fuel injection, while the main combustion chamber was fueled with lean mixture by the means of a carburetor. During the tests we have used two types of main combustion chamber and three types of secondary combustion chamber. Thus, we had the possibility to use different compression ratios, starting with the lower ones, imposed by the less volatile fuels and ending with the higher ones, that led to the highest output power and a steady working process. In the meantime, three types of spark plugs were tested. We have also studied the HC and CO emissions, as well as the fuel consumption.


Author(s):  
N Kalian ◽  
H Zhao ◽  
J Qiao

Controlled auto-ignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI), can be achieved by trapping residuals with early exhaust valve closure in a direct-fuel-injection in-cylinder four-stroke gasoline engine (through the employment of low-lift cam profiles). Because the operating region is limited to low-load and midload operation for CAI combustion with a low-lift cam profile, it is important to be able to operate spark ignition (SI) combustion at high loads with a normal cam profile. A 3.0l prototype engine was modified to achieve CAI combustion, using a cam profile switching mechanism that has the capability to switch between high- and low-lift cam profiles. A strategy was used where a high-lift profile could be used for SI combustion and a low-lift profile was used for CAI combustion. Initial analysis showed that for a transition from SI to CAI combustion, misfire occurred in the first CAI transitional cycle. Subsequent experiments showed that the throttle opening position and switching time could be controlled to avoid misfire. Further work investigated transitions at different loads and from CAI to SI combustion.


2019 ◽  
Vol 22 (1) ◽  
pp. 184-198
Author(s):  
Mikiya Araki ◽  
Katsuya Sakairi ◽  
Takashi Kuribara ◽  
Juan C González Palencia ◽  
Seiichi Shiga ◽  
...  

In a four-stroke cycle port-fuel-injected spark-ignition engine, a significant portion of unburned hydrocarbons is exhausted during the short period of cold start. The aim of this study is to investigate the physics behind the wall-wet phenomena and its determining parameter as simply as possible even though qualitative to some extent. The test engine is driven at a constant speed of 350 r/min. The fuel injection starts at a certain cycle, and the cycles required for the first ignition is counted. Three gasoline injectors having different atomization characteristics are used for port fuel injection, and the droplet size, the spray angle and the spray velocity are varied independently. The fuel transport phenomena from the injector to the cylinder are characterized by only two parameters, α and β, the mass fraction of the fuel without wall-wet and the mass fraction of the evaporated fuel from liquid films on walls. They are determined so that all the first ignition cycles observed experimentally are consistently reproduced by the model. The value of α is successfully determined for every single injector, and it increases monotonously with the decrease in the Stokes number.


2011 ◽  
Author(s):  
Cary W. Wilson ◽  
Frederick R. Schauer ◽  
Paul J. Litke ◽  
John L. Hoke ◽  
Jon-Russell J. Groenewegen

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