A Comparative Study of Alternative and Conventional Diesel Combustion Modes in a Single Cylinder Engine With a Single Injection Event

2016 ◽  
Author(s):  
Jim Cowart ◽  
Len Hamilton ◽  
Dianne Luning Prak
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Diffusion Flames ◽  
Single Injection ◽  
Direct Injection ◽  
Diesel Combustion ◽  
Intake Valve ◽  
Light Load ◽  
Combustion Modes ◽  
Start Of Injection

A broadly ranging single injection event was used in a Waukesha diesel CFR engine in order to explore various conventional and alternative combustion modes at light load (2 bar GMEP) using n-heptane fuel. Start of injection (SOI) was varied from the start of the intake valve open (IVO) event all the way past TDC at the end of the compression stroke. Emissions, including detailed particulate, were collected at all of the operating points. Additionally, further experiments were performed with port fuel injection in order to create a homogeneous charge compression ignition (HCCI) combustion mode as well as partially premixed combustion (PPC) using both port and direct fuel injection. HCCI and PPC combustion modes were achieved with the characteristic rise in carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions with however, a corresponding decrease in NOx emissions as compared to conventional direct (into cylinder) injection combustion modes. For conventional diesel operation with progressive advancement of SOI it was seen that start of combustion (SOC) advanced and then retarded slightly before stabilizing. This was associated with a general lengthening of ignition delay (IGD) with progressive SOI advancement. Even with very early intake valve open (IVO) injection events, the emissions behavior did not approach HCCI or PPC, suggesting that the charge mixture homogeneity of companion port injection could not be achieved in this engine using direct injection alone. High speed optical natural light filming of the combustion events through a large quartz window showed conventional diesel combustion with strong diffusion flames, reducing in intensity with PPC operation, and then no visible combustion with HCCI.

Visualization study of natural gas direct injection combustion

2003 ◽  
Vol 217 (8) ◽  
pp. 667-676 ◽  
Author(s):  
Z Huang ◽  
S Shiga ◽  
T Ueda ◽  
H Nakamura ◽  
T Ishima ◽  
...  
Keyword(s):  
Natural Gas ◽  
High Speed ◽  
Fuel Injection ◽  
Single Injection ◽  
Direct Injection ◽  
Video Camera ◽  
Injection Timing ◽  
Lean Combustion ◽  
High Speed Video Camera ◽  
Wrinkled Flame

A visualization study of natural gas direct injection combustion was carried out by using a high speed video camera. The results show that the distribution of the stratified mixture di ers with the injection mode, with parallel and single injection tending to form a higher degree of mixture stratification than opposed injection. Flame propagates toward the downstream direction in the cases of parallel and single-injection combustion, and flame propagates outward from the centre of the combustion chamber in the case of opposed injection combustion. A characteristic of turbulent combustion with a wrinkled flame front is presented in natural gas direct injection combustion. Super-lean combustion can be realized owing to the formation of an ignitable stratified mixture with the optimum setting of the fuel injection timing.

scholarly journals Impingement characteristics of an early injection gasoline direct injection engine: A numerical study

2016 ◽  
Vol 18 (4) ◽  
pp. 378-393 ◽  
Author(s):  
Nicholas J Beavis ◽  
Salah S Ibrahim ◽  
Weeratunge Malalasekera
Keyword(s):  
Liquid Film ◽  
Film Formation ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Gasoline Direct Injection ◽  
Intake Valve ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine ◽  
Start Of Injection ◽  
Early Injection

This article describes the use of a Lagrangian discrete droplet model to evaluate the liquid fuel impingement characteristics on the internal surfaces of an early injection gasoline direct injection engine. This study focuses on fuel impingement on the intake valve and cylinder liner between start of injection and 20° after start of injection using both a single- and a multi-component fuels. The single-component fuel used was iso-octane and the multi-component fuel contained fractions of iso-pentane, iso-octane and n-decane to represent the light, medium and heavy fuel fractions of gasoline, respectively. A detailed description of the impingement and liquid film modelling approach is also provided. Fuel properties, wall surface temperature and droplet Weber number and Laplace number were used to quantify the impingement regime for different fuel fractions and correlated well with the predicted onset of liquid film formation. Evidence of film stripping was seen from the liquid film formed on the side of the intake valve head with subsequent ejected droplets being a likely source of unburned hydrocarbons and particulate matter emissions. Differences in impingement location and subsequent location of liquid film formation were also observed between single- and multi-component fuels. A qualitative comparison with experimental cylinder liner impingement data showed the model to well predict the timing and positioning of the liner fuel impingement.

Multi-Valve High-Speed Direct Injection Diesel Engines—the Design Challenge

1993 ◽  
Vol 207 (4) ◽  
pp. 307-315
Author(s):  
I P Gilbert ◽  
A R Heath ◽  
I D Johnstone
Keyword(s):  
Diesel Engine ◽  
Fuel Economy ◽  
Cylinder Head ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Selection Strategy ◽  
Design Challenge ◽  
Hsdi Diesel Engine ◽  
High Level

The need to increase power, to improve fuel economy and to meet stringent exhaust emissions legislation with a high level of refinement has provided a challenge for the design of a compact high-speed direct injection (HSDI) diesel engine. This paper describes various aspects of cylinder head design with particular consideration of layout and number of valves, valve actuation, port selection strategy, fuel injection systems and cylinder head construction.

Combustion Characteristics of Methane Direct Injection Engine Under Various Injection Timings and Injection Pressures

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Characteristics ◽  
Direct Injection Engine ◽  
Optical Engine ◽  
Start Of Injection ◽  
Crank Angle ◽  
Combustion Speed ◽  
Injection Pressures

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.

A High-Speed Direct Injection Diesel Engine for Passenger Cars

1988 ◽  
Vol 202 (3) ◽  
pp. 171-181 ◽  
Author(s):  
J A Stephenson ◽  
B A Hood
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Passenger Cars ◽  
Medium Speed ◽  
Medium Speed Engine ◽  
Hsdi Diesel Engine ◽  
Wide Speed Range

The paper describes the development of a high-speed direct injection (HSDI) diesel engine suitable for passenger car applications. The evolution from a low emissions medium-speed engine, through a four-cylinder 2.3 litre research engine, into a four-cylinder 2.0 litre production engine is presented. The challenge to the engineer has been to develop the HSDI engine to operate with acceptable noise, emissions, smoke and driveability over the wide speed range (up to 5000 r/min) required for passenger cars. The key element in this task was the optimization of the combustion system and fuel injection equipment. The HSDI is shown to have a significant fuel economy advantage over the prechamber indirect injection (IDI) engine. Future developments of the fuel injection system are described which will further enhance the HSDI engine and provide additional noise and emissions control.

Detecting and Correcting Cylinder Imbalance in Direct Injection Engines

2000 ◽  
Vol 123 (3) ◽  
pp. 413-424 ◽  
Author(s):  
M. J. van Nieuwstadt ◽  
I. V. Kolmanovsky
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Direct Injection Engines ◽  
High Speed Diesel ◽  
On Line ◽  
Manufacturing Accuracy ◽  
Adaptation Scheme

Modern direct injection engines feature high pressure fuel injection systems that are required to control the fuel quantity very accurately. Due to limited manufacturing accuracy these systems can benefit from an on-line adaptation scheme that compensates for injector variability. Since cylinder imbalance affects many measurable signals, different sensors and algorithms can be used to equalize torque production by the cylinders. This paper compares several adaptation schemes that use different sensors. The algorithms are evaluated on a cylinder-by-cylinder simulation model of a direct injection high speed diesel engine. A proof of stability and experimental results are reported as well.

Combustion and Emission Characteristics of Direct-Injection Compression Ignition Engines by Means of Two-Stage Split and Early Fuel Injection

2002 ◽  
Vol 124 (3) ◽  
pp. 660-667 ◽  
Author(s):  
K. Yamane ◽  
Y. Shimamoto
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Emission Characteristics ◽  
Diesel Combustion ◽  
Compression Ignition ◽  
Two Stage ◽  
Di Diesel Engine ◽  
Early Injection

The objective of this study was to experimentally clarify the effect of two-stage split and early injection on the combustion and emission characteristics of a direct-injection (DI) diesel engine. Engine tests were carried out using a single-cylinder high-speed DI diesel engine and an injection system, combining an ordinary jerk pump and an electronically controlled high-pressure injection system, KD-3. In these experiments to compare the combustion and exhaust emission characteristics with two-stage split and early injection, a single-stage and early injection was tested. The FT-IR exhaust-gas analyzer simultaneously measured the exhaust emissions of 26 components. The results showed that HCHO, CH3CHO, and CH3COOH were emitted during the very early stage of both single injection and two-stage injection. These concentrations were higher than those from diesel combustion with ordinary fuel injection timings. These exhaust emissions are characteristic components of combustion by premixed compression ignition with extremely early injection. In particular, the HCHO concentration in exhaust was reduced with an increase in the maximum rate of heat release after cool flame due to pre-reaction of pre-mixture. At extremely early injection, the NOx concentration was extremely low; however, the indicated specific fuel consumption (ISFC) was higher than that of ordinary diesel combustion. In the case of two-stage injection, the degree of constant volume is increased, so that ISFC is improved. These results also demonstrated the possibility of reducing HCHO, NOx, and smoke emissions by means of two-stage split and early injection.

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