Development and Optimization of a Two-Valve Spark-Ignition Direct-Injection (SIDI) Small Block Engine

2013 ◽  
Author(s):  
David J. Cleary ◽  
Ronald O. Grover ◽  
David P. Sczomak
Keyword(s):  
Fuel Economy ◽  
Fuel Injection ◽  
Systems Approach ◽  
Direct Injection ◽  
Cold Start ◽  
Intake Manifold ◽  
Fuel Injector ◽  
Power Performance ◽  
Charge Motion ◽  
Small Block

A systems approach is implemented to fully optimize the overall performance of a gasoline SIDI two-valve “small block” engine. The objective is to maximize fuel economy while achieving significant improvements in idle stability, cold-start emissions, and torque and power performance relative a baseline port-fuel-injected (PFI) engine. The scope includes the optimization of the fuel injector, piston, cylinder head, cams, in-cylinder charge motion, and the intake-manifold. The results show that the SIDI engine provides the potential to achieve 6.5% better fuel economy; a result of higher efficiency when implementing a higher geometric compression ratio and significantly better combustion performance. A multiple fuel-injection strategy is examined to provide lower HC emissions at a representative cold-start operating condition. The engine’s idle stability is improved by a factor of three; the individual contributions from a better combustion system design and from multiple fuel injections are identified. The new SIDI engine concept demonstrated significantly better wide-open-throttle (WOT) performance, including up to 10% higher torque and 6% more power when using premium fuel. This document further demonstrates the performance sensitivity to engine design variables while emphasizing the importance of using a systems approach to achieve optimized performance for the direct-injection engine technology.

scholarly journals Rapid Liquid Fuel Mixing for Lean-Burning Combustors: Low-Power Performance

2001 ◽  
Vol 123 (3) ◽  
pp. 574-579 ◽  
Author(s):  
M. Y. Leong ◽  
C. S. Smugeresky ◽  
V. G. McDonell ◽  
G. S. Samuelsen
Keyword(s):  
Low Power ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Direct Injection ◽  
Fuel Injector ◽  
Power Performance ◽  
Lean Burn ◽  
Engine Operation ◽  
Turbine Engine ◽  
Lean Direct Injection

Designers of advanced gas turbine combustors are considering lean direct injection strategies to achieve low NOx emission levels. In the present study, the performance of a multipoint radial airblast fuel injector Lean Burn injector (LBI) is explored for various conditions that target low-power gas turbine engine operation. Reacting tests were conducted in a model can combustor at 4 and 6.6 atm, and at a dome air preheat temperature of 533 K, using Jet-A as the liquid fuel. Emissions measurements were made at equivalence ratios between 0.37 and 0.65. The pressure drop across the airblast injector holes was maintained at 3 and 7–8 percent. The results indicate that the LBI performance for the conditions considered is not sufficiently predicted by existing emissions correlations. In addition, NOx performance is impacted by atomizing air flows, suggesting that droplet size is critical even at the expense of penetration to the wall opposite the injector. The results provide a baseline from which to optimize the performance of the LBI for low-power operation.

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.

Investigation of a Novel Fuel Injection Technology Aimed to Reduce Cold-Start Emissions in SI Engines

2002 ◽  
Author(s):  
Brian T. Reese ◽  
Yann G. Guezennec ◽  
Miodrag Oljaca
Keyword(s):  
Fuel Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
The Novel ◽  
Fuel Injector ◽  
Si Engine ◽  
Fuel Droplets ◽  
Si Engines ◽  
Atomization Characteristics ◽  
Injection Technology

A novel fuel atomization device (Nanomiser™) was evaluated under laboratory conditions with respect to its ability to reduce SI engine cold-start hydrocarbon emissions. First, comparisons between the level of atomization using the conventional, pintle-type fuel injector and the novel atomizer were carried out using flow visualization in a spray chamber and particle size distribution. The novel atomizer is capable of producing sub-micron fuel droplets, which form an ultra-fine mist with outstanding non-wetting characteristics. To capitalize on these atomization characteristics, this device was compared to a conventional fuel injector in a small, two-cylinder, SI engine under a number of operating conditions. Results show a slightly enhanced combustion quality and lean limit under warm operating conditions and a dramatic reduction in unburned HC emission under cold operating conditions, with cold emissions with the Nanomiser™ matching those with a conventional injector under fully warm conditions.

scholarly journals Influence of Charge Motion and Compression Ratio on the Performance of a Combustion Concept Employing In-Cylinder Gasoline and Natural Gas Blending

2017 ◽  
Author(s):  
James Sevik ◽  
Michael Pamminger ◽  
Thomas Wallner ◽  
Riccardo Scarcelli ◽  
Steven Wooldridge ◽  
...  
Keyword(s):  
Natural Gas ◽  
Carbon Dioxide Emissions ◽  
Fuel Injection ◽  
Direct Injection ◽  
Peak Load ◽  
Charge Motion ◽  
Load Range ◽  
Absolute Increase ◽  
Efficient Operation ◽  
Indicated Mean Effective Pressure

The present paper represents a small piece of an extensive experimental effort investigating the dual-fuel operation of a light-duty spark ignited engine. Natural gas (NG) was directly injected into the cylinder and gasoline was injected into the intake-port. Direct injection of NG was used in order to overcome the power density loss usually experienced with NG port-fuel injection as it allows an injection after intake valve closing. Having two separate fuel systems allows for a continuum of in-cylinder blend levels from pure gasoline to pure NG operation. The huge benefit of gasoline is its availability and energy density, whereas NG allows efficient operation at high load due to improved combustion phasing enabled by its higher knock resistance. Furthermore, using NG allowed a reduction of carbon dioxide emissions across the entire engine map due to the higher hydrogen-to-carbon ratio. Exhaust gas recirculation (EGR) was used to (a) increase efficiency at low and part-load operation and (b) reduce the propensity of knock at higher compression ratios (CR) thereby enabling blend levels with greater amount of gasoline across a wider operating range. Two integral engine parameters, CR and in-cylinder turbulence levels, were varied in order to study their influence on efficiency, emissions and performance over a specific speed and load range. Increasing the CR from 10.5 to 14.5 allowed an absolute increase in indicated thermal efficiency of more than 3% for 75% NG (25% gasoline) operation at 8 bar net indicated mean effective pressure and 2500 RPM. However, as anticipated, the achievable peak load at CR 14.5 with 100% gasoline was greatly reduced due to its lower knock resistance. The in-cylinder turbulence level was varied by means of tumble plates as well as an insert for the NG injector that guides the injection “spray” to augment the tumble motion. The usage of tumble plates showed a significant increase in EGR dilution tolerance for pure gasoline operation, however, no such impact was found for blended operation of gasoline and NG.

Two-Stroke Engine with Fuel Semi-Direct Injection Using FAI System

2011 ◽  
Vol 130-134 ◽  
pp. 796-799
Author(s):  
Ming Ming Wu ◽  
Yan Xiang Yang ◽  
Da Guang Xi ◽  
Ping Zhang ◽  
Zhong Guo Jin
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Injection Timing ◽  
Fuel System ◽  
Power Performance ◽  
Fuel Injection Timing ◽  
Injection Quantity ◽  
Stroke Engine

This paper presents the feasibility of semi-direct injection on a 50cm3, two-stroke motorcycle gasoline engine, which is applied FAI semi-direct injection fuel system. The structure and fuel injection system is improved based on the original carburetor engine and the FAI injector is easily installed. The results of laboratory and drive test show that, compared with the original carburetor fuel system, through optimization calibration of fuel injection timing and injection quantity can improve power performance and fuel economy.

scholarly journals Rapid Liquid Fuel Mixing for Lean-Burning Combustors: Low-Power Performance

2000 ◽  
Author(s):  
May Y. Leong ◽  
Craig S. Smugeresky ◽  
Vincent G. McDonell ◽  
G. Scott Samuelsen
Keyword(s):  
Low Power ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Direct Injection ◽  
Fuel Injector ◽  
Power Performance ◽  
Lean Burn ◽  
Engine Operation ◽  
Turbine Engine ◽  
Lean Direct Injection

Designers of advanced gas turbine combustors are considering lean direct injection strategies to achieve low NOx emission levels. In the present study, the performance of a multipoint radial airblast fuel injector (“Lean Burn Injector—LBI”) is explored for various conditions that target low-power gas turbine engine operation. Reacting tests were conducted in a model can combustor at 4 atm and 6.6 atm, and at a dome air preheat temperature of 533 K, using Jet-A as the liquid fuel. Emissions measurements were made at equivalence ratios between 0.37 and 0.65. The pressure drop across the airblast injector holes was maintained at 3% and 7–8%. The results indicate that the LBI performance for the conditions considered is not sufficiently predicted by existing emissions correlations. In addition, NOx performance is impacted by atomizing air flows, suggesting that droplet size is critical even at the expense of penetration to the wall opposite the injector. The results provide a baseline from which to optimize the performance of the LBI for low-power operation.

scholarly journals Optical Characterization of a Multipoint Lean Direct Injector for Gas Turbine Combustors: Velocity and Fuel Drop Size Measurements

2010 ◽  
Author(s):  
Christopher M. Heath ◽  
Yolanda R. Hicks ◽  
Robert C. Anderson ◽  
Randy J. Locke
Keyword(s):  
Gas Turbine ◽  
Drop Size ◽  
Fuel Injection ◽  
Direct Injection ◽  
Operating Conditions ◽  
Diagnostic Methods ◽  
Spray Angle ◽  
Fuel Injector ◽  
Flame Tube ◽  
Component Velocity

Performance of a multipoint, lean direct injection (MP-LDI) strategy for low emission aero-propulsion systems has been tested in a Jet-A fueled, lean flame tube combustion rig. Operating conditions for the series of tests included inlet air temperatures between 672 K and 828 K, pressures between 1034 kPa and 1379 kPa and total equivalence ratios between 0.41 and 0.45, resulting in equilibrium flame temperatures approaching 1800 K. Ranges of operation were selected to represent the spectrum of subsonic and supersonic flight conditions projected for the next-generation of commercial aircraft. This document reports laser-based measurements of in situ fuel velocities and fuel drop sizes for the NASA 9-point LDI hardware arranged in a 3 × 3 square grid configuration. Data obtained represent a region of the flame tube combustor with optical access that extends 38.1-mm downstream of the fuel injection site. All data were obtained within reacting flows, without particle seeding. Two diagnostic methods were employed to evaluate the resulting flow path. Three-component velocity fields have been captured using phase Doppler interferometry (PDI), and two-component velocity distributions using planar particle image velocimetry (PIV). Data from these techniques have also offered insight into fuel drop size and distribution, fuel injector spray angle and pattern, turbulence intensity, degree of vaporization and extent of reaction. This research serves to characterize operation of the baseline NASA 9-point LDI strategy for potential use in future gas-turbine combustor applications. An additional motive is the compilation of a comprehensive database to facilitate understanding of combustor fuel injector aerodynamics and fuel vaporization processes, which in turn may be used to validate computational fluid dynamics codes, such as the National Combustor Code (NCC), among others.

Numerical analysis of the influence of early fuel injection on charge motion in a direct injection spark ignition engine using scale-resolving simulations

2019 ◽  
Vol 21 (4) ◽  
pp. 664-682
Author(s):  
Martin Theile ◽  
Martin Reißig ◽  
Egon Hassel ◽  
Dominique Thévenin ◽  
Martin Hofer ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Fuel Injection ◽  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Post Processing ◽  
Charge Motion ◽  
Set Up ◽  
Direct Injection Spark Ignition

This work summarizes the numerical analysis of the effect of early fuel injection on the charge motion in a direct injection spark ignition engine concerning cyclic fluctuations of the flow field. The combination of the scale-resolving turbulence model “Scale Adaptive Simulation” and post-processing routines for vortex trajectory visualization allows for a detailed insight into the temporal resolved and cycle-dependent behavior of the charge motion. In the first part, a simplified engine set-up is presented and used as a validation case to ensure correct behavior of the turbulence model and post-processing routines. In the second part, the computational fluid dynamics model of the real engine is introduced. The application of the proposed vortex tracking algorithm is shown, and a short discussion about the transient behavior of the charge motion in this engine set-up is given. The third part describes the analysis of the influence of the fuel injection on the charge motion at different engine speeds from 1000 to 3000 r/min and variations of the intake pressure from 1 to 2 bar. Finally, the impact on different flow field properties at possible ignition timings is discussed. Changes in mean flow field quantities as well as in aerodynamic fluctuations are found as a consequence of fuel injection.

scholarly journals Experimental study on the effects of the Miller cycle on the performance and emissions of a downsized turbocharged gasoline direct injection engine

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091872
Author(s):  
Zhao-Ming Huang ◽  
Kai Shen ◽  
Li Wang ◽  
Wei-Guo Chen ◽  
Jin-Yuan Pan
Keyword(s):  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Miller Cycle ◽  
Power Performance ◽  
Direct Injection Engine ◽  
Performance And Emission ◽  
Gasoline Direct Injection Engine ◽  
Partial Load

The Miller cycle has been proven to be an effective way to improve the thermal efficiency for gasoline engines. However, it may show insufficient power performance at certain loads. In this study, the objective is to exploit the advantages of the Miller-cycle engines over the original Otto-cycle engines. Therefore, a new camshaft profile with early intake valve closure was devised, and two various pistons were redesigned to obtain higher compression ratio 11.2 and 12.1, based on the original engine with compression ratio 10. Then, a detailed comparative investigation of the effects of Miller cycle combined with higher compression ratio on the performance and emission of a turbocharged gasoline direct injection engine has been experimentally carried out based on the engine bench at full and partial loads, compared to the original engine. The results show that, at full load, for a turbocharged gasoline direct injection engine utilizing the Miller cycle, partial maximum power is compromised about 1.5% while fuel consumption shows a strong correlation with engine speed. At partial load, since the Miller effect can well reduce the pumping mean effective pressure, thus improves the fuel economy effectively. In addition, the suppression of the in-cylinder combustion temperature induced by the lower effective compression ratio contributes to the reduction of nitrogen oxide emission greatly. However, the total hydrocarbon emission increases slightly. Therefore, a combination of the Miller cycle and highly boosted turbocharger shows great potential in further improvement of fuel economy and anti-knock performance for downsized gasoline direct injection engines.

Variable Fuel Placement Injector Development

2003 ◽  
Author(s):  
K. D. Brundish ◽  
M. N. Miller ◽  
L. C. Morgan ◽  
A. J. Wheatley
Keyword(s):  
High Pressure ◽  
Direct Injection ◽  
Design Flow ◽  
Combustion Stability ◽  
Development Work ◽  
Fuel Injector ◽  
Power Performance ◽  
Pressure Drops ◽  
Inlet Conditions ◽  
Aero Engines

This paper presents the progress made on the development of a dual spray, direct injection airblast fuel nozzle capable of variable fuel placement. It is anticipated that by varying the fuel placement within the confines of a combustion chamber it will be possible to control localised zonal ‘Fuel Air Ratio’ and thus extend both stability and emissions performance in respect of engine power range. The extension of combustion stability is particularly desirable to high pressure, temperature and turndown ratio aero engines where the ratio between maximum and flight idle fuel flow is extreme. Target performance data for the design has been derived from anticipated future engine cycles. A number of initial concepts were examined and recent development work has focused on the most successful design to date. Combustor testing has been performed at both atmospheric and high pressure. The combustor utilised was a single sector tubular combustor with combustor volume and airflow distributions representative of the cycle for which the fuel injector was designed. Two fuel injector configurations were examined, having different design flow structures. Combustion stability testing was performed with air inlet conditions of atmospheric pressure and 293K. Stability and ignition data were derived over a range of combustor pressure drops. Fuel injector AFRs of over 100:1 were achieved. An ignition loop was also derived although optimisation studies were not performed at this stage. High pressure emissions evaluation was also performed up to 13 Bar. Idle and scaled climb-out power conditions were tested, with a range of fuel scheduling between the pilot and main. Idle efficiency of over 99.5% was achieved. Low emissions performance was also achieved with less than 10 EINOx at climb out power settings. Future work will include testing at up to 40 Bar pressure to establish actual full power performance in addition to further development work on stability and ignition performance.

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