Combustion characteristics of a common rail direct injection engine using different fuel injection strategies

2018 ◽  
Vol 134 ◽  
pp. 475-484 ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Akhilendra Pratap Singh ◽  
Rakesh Kumar Maurya ◽  
Pravesh Chandra Shukla ◽  
Atul Dhar ◽  
...  
2019 ◽  
Vol 22 (1) ◽  
pp. 152-164 ◽  
Author(s):  
Ripudaman Singh ◽  
Taehoon Han ◽  
Mohammad Fatouraie ◽  
Andrew Mansfield ◽  
Margaret Wooldridge ◽  
...  

The effects of a broad range of fuel injection strategies on thermal efficiency and engine-out emissions (CO, total hydrocarbons, NOx and particulate number) were studied for gasoline and ethanol fuel blends. A state-of-the-art production multi-cylinder turbocharged gasoline direct injection engine equipped with piezoelectric injectors was used to study fuels and fueling strategies not previously considered in the literature. A large parametric space was considered including up to four fuel injection events with variable injection timing and variable fuel mass in each injection event. Fuel blends of E30 (30% by volume ethanol) and E85 (85% by volume ethanol) were compared with baseline E0 (reference grade gasoline). The engine was operated over a range of loads with intake manifold absolute pressure from 800 to 1200 mbar. A combined application of ethanol blends with a multiple injection strategy yielded considerable improvement in engine-out particulate and gaseous emissions while maintaining or slightly improving engine brake thermal efficiency. The weighted injection spread parameter defined in this study, combined with the weighted center of injection timing defined in the previous literature, was found well suited to characterize multiple injection strategies, including the effects of the number of injections, fuel mass in each injection and the dwell time between injections.


Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park

The performance of a methane direct injection engine was investigated under various fuel injection timings and injection pressures. A single-cylinder optical engine was used to acquire in-cylinder pressure data and flame images. An outward-opening injector was installed at the center of the cylinder head. Experimental results showed that the combustion characteristics were strongly influenced by the end of injection (EOI) timing rather than the start of injection (SOI) timing. Late injection enhanced the combustion speed because the short duration between the end of injection and the spark-induced strong turbulence. The flame propagation speeds under various injection timings were directly compared using crank-angle-resolved sequential flame images. The injection pressure was not an important factor in the combustion; the three injection pressure cases of 0.5, 0.8, and 1.1 MPa yielded similar combustion trends. In the cases of late injection, the injection timings of which were near the intake valve closing (IVC) timing, the volumetric efficiency was higher (by 4%) than in the earlier injection cases. This result implies that the methane direct injection engine can achieve higher torque by means of the late injection strategy.


2011 ◽  
Vol 110-116 ◽  
pp. 357-369 ◽  
Author(s):  
Raja Shahzad ◽  
P. Naveenchandran ◽  
A. Rashid ◽  
Amir Aziz

This paper discusses the combustion characteristics of CNG under lean and stochiometric conditions in a direct injection engine. The experiments were carried out on a dedicated CNG-Direct Injection engine with 14:1 compression ratio. Combustion characteristics of CNG have been investigated on various injection timings. Injection timing of the fuel injection timing had significant effects on the engine performance, combustion and emissions. The effects became more significant when injection timing was retarded. Injection timing was set after the closing of intake valve and experiments are conducted at 0% and 50% load conditions. Lean stratified operation experiences faster combustion compared to that of stochiometric. In lean stratified operation, there were fast burn rates at the initial stage and slower burning at the later stage. Whereas in stochiometric conditions there is a slightly slower burn at the initial stage and a moderately faster burn at the later stage. The faster initial combustion in lean stratified operation might be due to rapid burn of the initial mixture due to higher turbulence, while a slower burn in the later stage due to diffusion. In contrary to that in stochiometric operations the initial burn is slightly slower, due to moderately strong turbulence and a faster burn due to moderately proceeding mixture. Thus the main effect of fuel injection timing can be explained by the fuel air mixing and the turbulence produced.


Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park

The performance of a methane direct injection engine was investigated under various fuel injection timings and injection pressures. A single-cylinder optical engine was used to acquire in-cylinder pressure data and flame images. An outward-opening injector was installed at the center of the cylinder head. Experimental results showed that the combustion characteristics were strongly influenced by the end of injection timing rather than the start of injection timing. Late injection enhanced the combustion speed because the short duration between the end of injection and the spark induced strong turbulence. The flame propagation speeds under various injection timings were directly compared using crank-angle-resolved sequential flame images. The injection pressure was not an important factor in the combustion; the three injection pressure cases of 0.5, 0.8, and 1.1 MPa yielded similar combustion trends. In the cases of late injection, the injection timings of which were near the Intake Valve Closing (IVC) timing, the volumetric efficiency was higher (by 4%) than in the earlier injection cases. This result implies that the methane direct injection engine can achieve higher torque by means of the late injection strategy.


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