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Experimental Investigation of the Compression Ignition Process of High Reactivity Gasoline Fuels and E10 Certification Gasoline using a High-Pressure Direct Injection Gasoline Injector

Aramco Services Co.-Tom Tzanetakis
Michigan Technological University-Jiongxun Zhang, Meng Tang, William Atkinson, Henry Schmidt, Seong-Young Lee, Jeffrey Naber
  • Technical Paper
  • 2020-01-0323
To be published on 2020-04-14 by SAE International in United States
Gasoline compression ignition (GCI) technology shows potential to obtain high thermal efficiencies while maintaining relatively low soot and NOx emissions in light-duty engine applications. Recent experimental studies and numerical simulations have indicated that high reactivity gasoline-like fuels can further enable the benefits of GCI combustion. However, there is limited combustion data in the literature studying the gasoline compression ignition process at relevant in-cylinder conditions which are required for further optimizing combustion system designs. This study investigates the temporal and spatial evolution of the compression ignition process of various high reactivity gasolines with research octane numbers (RON) of 71, 74 and 82, as well as conventional RON 97 E10 gasoline fuel. Combustion visualizations were conducted in an optically accessible constant volume combustion chamber. A ten-hole prototype gasoline injector specifically designed for GCI applications to be capable of injection pressure of up to 450 bar was used. OH* chemiluminescence and natural luminosity images were recorded simultaneously to characterize the ignition process through two high speed cameras. The experiments were conducted under a wide range of ambient charge…
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Spark Mechanism in High Speed Flow

Michigan Technological University-Mary P. Zadeh, Henry Schmidt, William Atkinson, Jeffrey Naber
Published 2019-04-02 by SAE International in United States
An experimental study was performed to investigate spark ignition and subsequent spark stretch evolution in an inert environment at high- flow velocities up to 32 m/s across the spark plug gap in a constant-volume optical combustion-vessel at pressures representative of those in an engine. The vessel is capable of generating various in-cylinder thermodynamic conditions representative of light-duty spark ignition engines. The characteristic behavior of the spark was investigated using both a high-speed optical diagnostics and electrical measurement. Charge gas pressures were varied from 15 to 45 bar. Results show that the spark, flowing downstream the spark plug, is subject to short circuits of the spark channel and/or restrikes. The frequency of the restrike increased with increased flow velocity and charge gas pressure and decreased discharge current level. The position of the ground electrode with respect to the flow and the gap size, as well as the flow velocity and charge gas pressure, were determined to have a significant influence on spark plasma development and electrical discharge prediction. It was observed that a wider spark plug…
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Process for Study of Micro-pilot Diesel-NG Dual Fuel Combustion in a Constant Volume Combustion Vessel Utilizing the Premixed Pre-burn Procedure

Michigan Technological University-Xuebin Yang, Vinicius Bonfochi Vinhaes, Jeffrey Naber, Mahdi Shahbakhti, Henry Schmidt, William Atkinson
Westport Fuel Systems-Marco Turcios, Gordon McTaggart-Cowan
Published 2019-04-02 by SAE International in United States
A constant volume spray and combustion vessel utilizing the pre-burn mixture procedure to generate pressure, temperature, and composition characteristic of near top dead center (TDC) conditions in compression ignition (CI) engines was modified with post pre-burn gas induction to incorporate premixed methane gas prior to diesel injection to simulate processes in dual fuel engines. Two variants of the methane induction system were developed and studied. The first used a high-flow modified direct injection injector and the second utilized auxiliary ports in the vessel that are used for normal intake and exhaust events. Flow, mixing, and limitations of the induction systems were studied. As a result of this study, the high-flow modified direct injection injector was selected because of its controlled actuation and rapid closure.Further studies of the induction system post pre-burn were conducted to determine the temperature limit of the methane auto-ignition. It was found that for sufficient induction and mixing time determined from experimental observations and CFD modeling studies, a maximum core temperature of 750 K at the time of micro-pilot diesel injection can…
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Influence of Elevated Injector Temperature on the Spray Characteristics of GDI Sprays

Michigan Technological University-Niranjan Miganakallu Narasimhamurthy, William Atkinson, Zhuyong Yang, Jeffrey Naber
Published 2019-04-02 by SAE International in United States
When fuel at elevated temperatures is injected into an ambient environment at a pressure lower than the saturation pressure of the fuel, the fuel vaporizes in the nozzle and/or immediately upon exiting the nozzle; that is, it undergoes flash boiling. It is characterized by a two-phase flow regime co-located with primary breakup, which significantly affects the spray characteristics. Under flash boiling conditions, the near nozzle spray angle increases, which can lead to shorter penetration because of increased entrainment. In a multi-hole injector this can cause other impacts downstream resulting from the increased plume to plume interactions.To study the effect of injector temperature and injection pressure with real fuels, an experimental investigation of the spray characteristics of a summer grade gasoline fuel with 10% ethanol (E10) was conducted in an optically accessible constant volume spray vessel. A gasoline direct-injection injector with six holes typical of a side-injection engine was studied. Optical diagnostics included high-speed photography with alternate frame imaging from Mie-Scattering and Shadowgraph techniques. Ambient conditions representing Early Injection (45°C, 1 bar) and Late Injection (180°C,…
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Water Injection as an Enabler for Increased Efficiency at High-Load in a Direct Injected, Boosted, SI Engine

SAE International Journal of Engines

Michigan Tech APS Labs-Jeremy Worm, Jeffrey Naber, Joel Duncan
Nostrum Energy LLC-Sam Barros, William Atkinson
  • Journal Article
  • 2017-01-0663
Published 2017-03-28 by SAE International in United States
In a Spark-Ignited engine, there will come a point, as load is increased, where the unburned air-fuel mixture undergoes auto-ignition (knock). The onset of knock represents the upper limit of engine output, and limits the extent of engine downsizing / boosting that can be implemented for a given application. Although effective at mitigating knock, requiring high octane fuel is not an option for most markets. Retarding spark timing can extend the high load limit incrementally, but is still bounded by limits for exhaust gas temperature, and spark retard results in a notable loss of efficiency. Likewise, enriching the air-fuel mixture also decreases efficiency, and has profound negative impacts on engine out emissions. In this current work, a Direct-Injected, Boosted, Spark-Ignited engine with Variable Valve Timing was tested under steady state high load operation. Comparisons were made among three fuels; an 87 AKI, a 91 AKI, and a 110 AKI off-road only race fuel. The engine was outfitted with a sequential port water injection apparatus. Under full-load, water injection enabled operation with 87 AKI fuel at…
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Investigation of Multi-Hole Impinging Jet High Pressure Spray Characteristics under Gasoline Engine-Like Conditions

Le Zhao
Michigan Technological University-Ahmed Abdul Moiz, Seong-Young Lee, Jeffrey Naber
Published 2016-04-05 by SAE International in United States
Impingement of jet-to-jet has been found to give improved spray penetration characteristics and higher vaporization rates when compared to multi-hole outwardly injecting fuel injectors which are commonly used in the gasoline engine. The current work studies a non-reacting spray by using a 5-hole impinging-jet style direct-injection injector. The jet-to-jet collision induced by the inwardly opening nozzles of the multi-hole injector produces rapid and short jet breakup which is fundamentally different from how conventional fuel injectors operate. A non-reacting spray study is performed using a 5-hole impinging jet injector and a traditional 6-hole Bosch Hochdruck-Einspritzventil (HDEV)-5 gasoline direct-injection (GDI) injector with gasoline as a fuel injected at 172 bar pressure with ambient temperature of 653 K and 490 K and ambient pressure of 37.4 bar and 12.4 bar. The engine-like thermodynamic conditions were generated in a constant-volume high pressure-temperature preburn type combustion vessel for the two corresponding SI engine conditions. In addition, Computational fluid dynamics (CFD) work has been performed using an Eulerian-Lagrangian modelling approach. Iso-octane was used as a fuel in simulation for both injectors.…
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Numerical Simulations for Spray Characterization of Uneven Multiple Jet-to-Jet Impingement Injectors

Le Zhao
Michigan Technological Univ.-Sanjeet Limbu, Sathya Prasad Potham, Seong-Young Lee, Jeffrey Naber
Published 2016-04-05 by SAE International in United States
Spray structure has a significant effect on emissions and performance of an internal combustion engine. The main objective of this study is to investigate spray structures based on four different multiple jet impingement injectors. These four different multiple jet-to-jet impingement injectors include 1). 4-hole injector (Case 1), which has symmetric inwardly opening nozzles; 2). 5-1-hole (Case 2); 3). 6-2-hole (Case 3); and 4). 7-3-hole (Case 4) which corresponding to 1, 2, 3 numbers of adjacent holes blocked in a 5-hole, 6-hole, and 7-hole symmetrical drill pattern, respectively. All these configurations are basically 4-holes but with different post collision spray structure. Computational Fluid Dynamics (CFD) work of these sprays has been performed using an Eulerian-Lagrangian modelling approach. First, the present work visualizes spray structures and explores the trend of ‘post collision’ and ‘bend’ angles of four different injectors in two different clip-plane views which are named View 1 and View 2. Pressure and velocity fields in spray chamber are analyzed to study their effects on spray structures. Finally, mass and droplet size distributions are employed to…
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Extraction of Liquid Water from the Exhaust of a Diesel Engine

Nostrum Energy LLC-Sam Barros, William Atkinson, Naag Piduru
Published 2015-09-29 by SAE International in United States
Introducing water in a diesel engine has been known to decrease peak combustion temperatures and decrease NOx emissions. This however, has been limited to stationary and marine applications due to the requirement of a separate water supply tank in addition to the fuel tank, thereby a two-tank system. Combustion of hydrocarbon fuels produce between 1.35 (Diesel) and 2.55 times (Natural Gas) their mass in water. Techniques for extracting this water from the exhaust flow of an engine have been pursued by the United States department of defense (DOD) for quite some time, as they can potentially reduce the burden of supply of drinking water to front line troops in theater. Such a technology could also be of value to engine manufacturers as it could enable water injection for performance, efficiency and emissions benefits without the drawbacks of a two-tank system. In this paper, a technique where the exhaust is first cooled via a modified EGR cooler and then passed through a cyclonic separator to separate heavier liquid particles from the exhaust gas flow is demonstrated.…
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High-Speed Spray-to-Spray Collision Study on Two-Hole Impinging Jet Nozzles

Michigan Technological Univ-Le (Emma) Zhao, Ahmed Abdul Moiz, Jeffrey Naber, Seong-Young Lee
Nostrum Energy LLC-Sam Barros, William Atkinson
Published 2015-04-14 by SAE International in United States
High-speed spray-to-spray liquid impingement could be an effective phenomenon for the spray propagation and droplet vaporization. To achieve higher vaporization efficiency, impingement from two-hole nozzles is analyzed in this paper. This paper focuses on investigating vaporization mechanism as a function of the impingement location and the collision breakup process provided by two-hole impinging jet nozzles. CFD (Computational Fluid Dynamics) is adopted to do simulation. Lagrangian model is used to predict jet-to-jet impingement and droplet breakup conditions while KH-RT breakup and O'Rourke collision models are implemented for the simulation. The paper includes three parts: First, a single spray injected into an initially quiescent constant volume chamber using the Lagrangian approach is simulated to identify the breakup region, which will be considered as a reference to study two-hole impinging jet nozzles. Lagrangian simulation results would be validated via experimental results. Second, collision mechanism is analyzed to obtain probability distribution of collision efficiency and study the jet-to-jet impingement. Finally, the paper examines the collision phenomenon under engine-like conditions, to examine impingement at pre (case 1), exact (case 2),…
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