bluuebunny/crossref_metadata_2025 huggingface dataset:
Development Of On-board Multi-component Gas Analyzer Toward Euro 7
Authors: Kondo Yosuke , Hamauchi Shota , Kowada Yoshihito , Shibuya Kyoji , Otsuki Yoshinori
Published: November 2023

The Euro 7 emission regulations currently under consideration by the EU will adopt on-road emissions test as the main Type Approval procedure, and it has been proposed that the number of gas components to be measured will be increased. Therefore, the Portable Emissions Measurement System (PEMS) used for on- road emissions testing must be able to simultaneously measure more components with higher precision while maintaining the same compact and lightweight structure as in the existing PEMS. The authors have applied a relatively new technique, quantum cascade laser infrared spectroscopy (QCL-IR), to an on-board multi-component gas analyzer. Comparison with laboratory tests on a gasoline passenger car on a dynamometer showed that the newly developed QCL- IR PEMS correlated well with conventional PEMS and stationary conventional analyzers. Signal noise and interference from other gases was also confirmed to show the expected performance, which was equal to or better than that of conventional analyzers.
Impact from a variety of E10 and E20 gasoline formulations on PN10
and PN23 emissions evaluated in combination with advanced GPF technology
generations
Authors: Chijiiwa Ryoko , Rose Dominik , Boger Thorsten , Krueger-Venus Jens , Cracknell Roger , Williams Rod
Published: November 2023

The study was aimed at assessing the impact of fuel quality on the PN10 and PN23
emissions. A total of 6 fuels having different level of ethanol, renewable
components, additives, and aromatic hydrocarbons were tested on the test
vehicle. In the first phase of the study, the emission tests were conducted
removing the GPF present in the original aftertreatment system to measure the
direct impact of different fuels on the tailpipe particle emissions. The
emission results showed that heavy aromatics components lead to a significant
increase in particle emissions while the fuel with renewable components and E20
emit less PN comparing to the E10 reference fuel. However, those fuel impacts
became very small with a GPF present due to a high filtration efficiency
independent of fuel type.
Effects of oxygenate and aromatic content on engine-out aldehyde emissions from pure, binary, and ternary mixtures of ethanol, toluene, and iso-octane
Authors: Shankar Varun , Leach Felix
Published: November 2023

Sustainable fuel components, such as ethanol, can be blended into gasoline to help reduce fossil fuel consumption. Aldehydes are both observed emissions and major intermediates in the oxidation of gasoline/ethanol fuel mixtures and are solely attributed to the fuel’s alcohol content.

This study aims to evaluate the direct impact of toluene, iso-octane, and ethanol on engine-out formaldehyde and acetalde hyde emissions. A single-cylinder direct injection spark ignition engine was run at low speed and load conditions with varying equivalence ratios. The emissions are measured using a FTIR.

The aldehyde emissions from pure ethanol are ten- and five- times greater than pure toluene and iso-octane, respectively. Greater formaldehyde than acetaldehyde is found for iso-octane and toluene and vice versa for ethanol. The addition of 25 %vol of toluene to ethanol halves the average aldehyde emissions due to toluene suppressing effects. In the ternary mixtures with fixed ethanol content, the higher toluene concentration mixture led to lower average aldehyde emissions.
Low Ash SP/GF-6 Fuel Eco Gasoline Engine Oil
Authors: Yamada Naohiro , Nakano Seiichi , Koike Yusuke , Suzuki Rika , Okuda Sachiko , Konishi Shozaburo
Published: November 2023

A gasoline particulate filter (GPF) is installed in a passenger vehicle for new exhaust regulation. However, ash in gasoline engine oil has a risk of clogging as well as performance decrease in the GPF. Therefore, new gasoline engine oil whose ash contents decrease to 0.8 mass% was developed in order to avoid the GPF clogging. In addition to this, our developed oil improves fuel efficiency (+0.2% from our SN 0W-16 fuel eco type oil) as well as anti-wear performance for gasoline engine, which resulted in meeting API SP/ILSAC GF-6 0W-16 official certification.
Hydrogen Combustion using Port-fuel Injections in a Heavy-Duty Optical Diesel Engine Converted to Spark Ignition Operation
Authors: Panthi Niraj , Sharma Priybrat , AlRamadan Abdullah S. , Cenker Emre , Magnotti Gaetano
Published: November 2023

This study examines the use of hydrogen as a fuel for internal combustion engines to decrease greenhouse gas emissions. The focus is on hydrogen combustion at leaner mixture conditions, which has the potential to increase efficiency and reduce NOx emissions. While metal engine experiments have established these benefits, there are only a few optical studies on pure hydrogen combustion under lean operating conditions. This study reports optical measurements performed in a heavy-duty optical diesel engine converted to spark-ignition operation with port-fuel injections and varying spark timing, at air-excess ratios (lambda) of 2.5 and 3. The engine was equipped with a flat-shaped optical piston that allowed for bottom-view imaging of the combustion process. High-speed natural combustion luminosity images were recorded, along with in-cylinder pressure measurements. The results showed that advancing the spark timing shifted the combustion phasing towards TDC, thus increasing the peak combustion pressure for both tested lambda values. The peak combustion pressure decreased at the higher lambda operating point. The shortest combustion duration was associated with the minimum COV of IMEPg, indicating the optimal spark timing configuration for pure hydrogen combustion under lean conditions. The study also analyzed the high-speed natural combustion luminosity images to determine the flame front propagation speed, which increased rapidly during the early stage of combustion, reached a peak, and then decreased. The highest peak flame front propagation speed of 19.62 m/s was observed for a spark timing of -20°CA aTDC at a lambda value of 2.5.
Numerical Investigation for Carcinogenicity and Mutagenicity Potential of PAHs Emitted from Hydrogen/diesel Dual-fuel Engine
Authors: Yadav Neeraj Kumar , Saxena Mohit Raj , Maurya Rakesh Kumar
Published: November 2023

This study numerically investigates the toxicity potential of polycyclic aromatic hydrocarbon (PAHs) emitted from conventional diesel and hydrogen–diesel dual-fuel combustion engine. The simulations are performed on ANSYS Forte using a detailed chemical reaction mechanism of diesel surrogate (66.8% n − decane/33.2% alpha − methylnaphthalene). The used reaction mechanism consists of 189 species and 1392 reactions. The study numerically predicts the concentration of eight toxic PAHs (naphthalene, phenanthrene, acenaphthene, pyrene, chrysene, benzo[a]pyrene, benzo perylene, and benzo [g, h, i] perylene) emission for which carcinogenicity and mutagenicity potential is determined. Results demonstrate that hydrogen-diesel dual-fuel engine has lower carcinogenicity and mutagenicity potential than the conventional diesel engine.
Experimental and Numerical Assessment of Engine Performance Using Cyclopentanone and Anisole as Neat Fuels and as Blends with Gasoline
Authors: Burkardt Patrick , Günther Marco , Pischinger Stefan
Published: November 2023

The dilution of the cylinder charge using excess air enables both an increase in the net indicated efficiency and a decrease in the engine-out emissions of nitrogen oxides. The maximum excess air dilution capability in a spark-ignition engine depends on both the ignition of the charge and the flame propagation. These two aspects can be influenced by the fuel properties, which draw attention to the laminar burning velocity of alternative fuels to extend the lean limit. Cyclopentanone and anisole show promising values regarding the laminar burning velocity. However, there is a lack of engine investigations using these two fuels. To this end, both fuels were assessed in an engine application using experimental and numerical investigations. Cyclopentanone and anisole were investigated as neat components and as mixtures with conventional gasoline fuel, resulting in seven investigated fuels. The engine performances of all seven fuels were assessed in variations of the excess air ratio at net indicated mean effective pressures of 6 bar and 15 bar at an engine speed of 2000 1/min using a spark-ignition single-cylinder engine for passenger car applications. Moreover, numerical 3D simulations were performed at the lean limit. The application of neat cyclopentanone achieved the highest increase in the excess air ratio up to 1.75, resulting in a net indicated efficiency of 42.7%. Using neat anisole, a maximum excess air ratio of 1.6 was achieved, which was the same maximum as with the conventional gasoline fuel. The numerical investigations revealed a pronounced mixture stratification with an increased anisole fraction, resulting in a poor combustion efficiency and high emissions of nitrogen oxides. This work provides fundamental insights into the engine performance of cyclopentanone and anisole to further consider them as neat fuels and as blend components.
Mechanism for Internal Injector Deposits Formation in Heavy-duty Engines using Drop-in Fuels
Authors: Pach Mayte , Hittig Henrik , Couval Romain , Kusar Henrik , Engvall Klas
Published: November 2023

Heavy-duty transportation is one of the sectors that contributes to greenhouse gas emissions. One way to reduce CO2 emissions is to use drop-in fuels. However, when drop-in fuels are used, i.e., higher blends of alternative fuels are added to conventional fuels, solubility problems and precipitation in the fuel can occur. As a result, insolubles in the fuel can clog the fuel filters and interfere with the proper functioning of the injectors. This adversely affects engine performance and increases fuel consumption. These problems are expected to increase with the development of more advanced fuel systems to meet upcoming environmental regulations. This work investigates the composition of the deposits formed inside the injectors of the heavy-duty diesel engine and discusses their formation mechanism. Injectors with internal deposits were collected from field trucks throughout Europe. Similar content, location and structure were found for all the deposits in the studied injectors. The physical structure was analyzed using a Scanning Electron Microscope with an Energy Dispersive X-Ray (SEM-EDX). Pyrolysis coupled with Gas Chromatography Mass Spectrometry (Py GC-MS) and Fourier-transform Infrared Spectroscopy (FTIR) were also used to determine the composition of the injector deposits. The deposits consist of a mixture of organic and inorganic compounds, indicating that they originate from fuel and engine oil. To further analyze the origin of the formed deposits, samples were collected from various parts of the fuel system. The analysis suggests that the deposits were formed exclusively in the injectors, and by comparing and describing the composition and structure of the deposits from different parts of the injector, a mechanism is proposed.
The influence of fluid properties on near nozzle sprays in clean and fouled GDI injectors
Authors: Gander Alex , de Sercey Guillaume , Crua Cyril
Published: November 2023

Physical fluid properties and GDI injector deposits are known to impact the internal nozzle flow and external spray morphology. Furthermore, deposits can affect injector calibration and damage the delicate mixing and combustion processes. Despite this, there is a lack of experimental data demonstrating the discrete influence of fluid properties and how this influence evolves with the formation of injector deposits. This article aims to further the existing knowledge on the effect of fluid properties such as density, kinematic viscosity and surface tension, along with distillation on fuel spray characteristics and provide insight into how sprays change over the lifetime of GDI injectors due to fouling. In this investigation, four gasoline fuels with varying concentrations of ethanol and typical GDI additive, including one being representative of a renewable gasoline formulation, were used with clean and fouled multi-hole GDI fuel injectors. A low-pressure constant-volume chamber was used to produce a controlled inert atmosphere at various ambient and injection conditions. Shadowgraph images were recorded using two high- speed cameras at the micro and macro scales to simultaneously visualise the fluid dynamic processes in the near nozzle and downstream regions. Image analysis demonstrated that fouling had a significant impact on the spray angle. Standard error of the mean was used to determine the repeatability of the measurements taken, and it was found that the spray width at the nozzle tip had a very low standard error. In contrast, a comparatively high standard error was calculated for spray dispersion angle exhibited for the fouled and clean injectors. Due to high repeatability on spray width measurements, positive correlations were found between the spray width at the nozzle tip and initial boiling point, surface tension and kinematic viscosity, and negative correlations with density and final boiling point.
Research on Super-Lean Burn Spark Ignition Engine with In-Cylinder Water Injection using Gasoline Surrogate Fuels
Authors: Nagasawa Tsuyoshi , Ishibashi Soh , Kosaka Hidenori
Published: November 2023

The combination of super-lean burn spark ignition engine (excess air ratio λ ≈ 2) and in-cylinder water injection (WI) makes it possible to achieve thermal efficiency higher than 50%. Toward future fuel diversification including carbon-neutral fuels, technologies to improve SI engine thermal efficiency applicable to various fuels are required. In this study, the effect of in-cylinder WI on SI engine performance with a compression ratio of 17 and λ = 1.85 is investigated using premium gasoline, 5 components surrogate fuels for premium gasoline (S5H), and for regular gasoline (S5R). In the case of premium gasoline and S5H, spark timing can be advanced to MBT (minimum advance for best torque) by WI and gross indicated thermal efficiency (gITE) increases to 51.2% (premium gasoline) at water/fuel weight ratio (W/F) = 57.7% and 50.8% (S5H) at W/F = 62.9%. In the case of S5R, on the other hand, a strong knock forces a large spark retard at no-water condition. Although the water injection suppresses the knock and gives spark advance, the spark timing cannot be advanced to the region where stable lean combustion can be achieved. As a result, the maximum gITE for S5R only increases to 45.1% by WI of W/F = 69.3%. These results show that the effect of thermal efficiency improvement by WI can be obtained regardless of the fuel while a fuel with high knock resistance is required to achieve compatibility with super-lean burn.
Research on Wall Temperature of Flame-wall Interaction Based on Laser-Induced Phosphorescence and Heat Transfer Simulation
Authors: Xuefeng XUE , Run CHEN , Tie LI , Xinyi ZHOU , Jiale CAO , Xin TANG
Published: November 2023

Heavy heat load is one of the bottlenecks restricting the highly intensive marine engine development. Reducing wall heat loss contributes to this target. The wall heat transfer is mainly influenced by flame-wall interaction (FWI). In this paper, a wall temperature distribution measurement system is developed based on the Laser-Induced Phosphorescence (LIP). The effects of the coating thickness and the laser fluence on LIP are studied to clarify the accuracy of wall temperature measurement based on LIP and the one-dimensional wall temperature distribution. In addition, a conjugate heat transfer model of FWI was established based on CONVERGE to simulate the FWI and the accompanying heat transfer process. The simulation is compared with the experimental wall temperature results and demonstrates the effectiveness of the conjugate heat transfer model. The influence of the initial velocity, the impinging distance and the wall roughness on the wall heat transfer are studied. The effective way to reduce the wall heat loss is explored, and the conjugate heat transfer model of FWI is considered to be potential to contribute to the mechanism research of FWI.
Visualization of Combustion and Flow Phenomena in a Methane-Fueled Passive Pre-Chamber Ignited Gas Engine
Authors: KHAN MD Tanvir , KAWAHARA Nobuyuki , KOBASHI Yoshimitsu , HIRAYAMA Towa , SHIMIZU Ayumi , MIYAMOTO Sekai
Published: November 2023

This study aims to investigate the combustion and flow phenomena in a stoichiometrically operated methane-fueled passive pre-chamber ignited gas engine. The combustion phenomena are visualized with a high-speed camera and the chemical properties are resolved by Large Eddy Simulation (LES) turbulent model with the SAGE combustion approach. Results reveal that a highly compressed unburnt gas of intermediate fuel species emerges from the pre-chamber before the flame ejection due to the high-pressure difference which promptly consumes the main chamber charge and accelerates combustion. Moreover, the nozzle diameter and spark plug orientation significantly affect the flame propagation as well as the overall engine performance.
Ignition and Combustion Controls of Synthetic Fuel using Diesel Engine with Variable Valve Timing System [First Report]
Authors: Sumida Yo , Terada Masaya , Kawano Daisuke
Published: November 2023

Because the transportation industry uses fossil fuels as much as 1/4 of the total, CO2 emission from transport sector should be reduced. Therefore, carbon neutral (CN) fuel has been attracted attention. However, hydrogen and ammonia have low energy density and are difficult to be stored and transported. In this study, synfuel produced by Fischer-Tropsch (FT) reaction. This fuel is produced with carbon dioxide absorbed from the direct air capture and electricity derived from renewable energy, so it is possible to achieve CN. However, FT fuel tends to have less aromatics and a higher cetane number than diesel fuel. Therefore, excessive early ignition occurs at low speed and low load in application to diesel engine. The purpose of this study is to suppress early ignition by controlling the amount of air flowing into the cylinder. The numerical results showed that the ignition timing and combustion could be controlled using Miller cycle by late intake valve closing (LIVC). In addition, by controlling the ignition timing with LIVC, it became possible to prolong the ignition delay period, and premixed charge compression ignition (PCCI) combustion was realized in the low-speed low-load region. This combustion improved indicated mean effective pressure with high degree of constant volume. Additionally, decrease in fuel-rich zones derived from long ignition delay period reduced NOx and soot emissions. From the above, the possibility of improving combustion and exhaust emission performances by applying the Miller cycle using LIVC when using FT fuel was demonstrated.
New Concept Exhaust Manifold for Next-Generation HEV and PHEV
Authors: Ito Hirokazu , Seguchi Kazuhiko , Nakayama Shigeki , Fukuma Takao
Published: November 2023

HEV and PHEV require an improved aftertreatment system to clean the exhaust gas in various driving situations. The efficiency of aftertreatment system is significantly influenced by the residence time of the gas in a catalyst which gas flow has generally strong pulsation. Simulation showed up to 70% reduction of exhaust gas emission if the pulsation could be completely attenuated. A new concept exhaust manifold was designed to minimize pulsation flow by wall impingement, with slight increase of pressure loss. Experimental results with new concept exhaust manifold showed exhaust gas emission were reduced 16% at cold condition and 40% at high-load condition.
Analysis of Standby Power in an Enclosed High-Speed Flywheel Energy Storage System Using the CFD-ANOVA Approach
Authors: Eltaweel Mahmoud , Herfatmanesh Mohammad Reza
Published: November 2023

During urban driving, a significant amount of energy is lost due to continuous braking, which can be recovered and stored. The flywheel energy storage system (FESS) can efficiently recover and store the vehicle's kinetic energy during deceleration. However, standby losses in FESS, primarily due to aerodynamic drag, can affect its overall efficiency. To address this issue, the flywheel rotor is typically housed in a dedicated housing maintained at a low pressure using a vacuum pump. Standby power is known as the total power used by the auxiliary systems and the power needed to overcome drag and keep the flywheel rotor at a specific state of charge. The Analysis of Variance (ANOVA) technique was combined with the computational fluid dynamics (CFD) technique in this study to determine the optimal flywheel design parameters and investigate their impact on standby power. The study's results demonstrated the optimal combination of the airgap size and the rotor's pressure cavity to achieve the lowest standby power.
Development of 1D vehicle energy flow model to select suitable thermal system configuration and components
Authors: Yamashita Hayato , Kojima Takayoshi , Ueki Takeshi , Hiai Daisuke , Sakushima Nobuyuki
Published: November 2023

In case of electric vehicle (EV), as there are various thermal system configurations in each automotive manufacturer, suppliers should take a huge amount of time to select the best components for each OEM system. To solve this problem, a model-based development (MBD) method switching components easily and estimating their benefits efficiently is needed. In this study, the vehicle energy flow model was developed to select appropriate system configuration and components to balance cabin comfort and battery lifetime. To realize required accuracy and computing time, a 1D model, which has a motor, an air-cooling battery, a coolant circuit and heating ventilation and air-conditioning (HVAC) in a cabin, based on C-segment vehicle, was developed.
Study on Novel Combustion Technologies to Achieve “High-heels” Heat Release Rate Profile in a Higher-compression-ratio Diesel Engine
Authors: Uchida Noboru , Watanabe Kazumasa
Published: November 2023

For further increase in thermal efficiency of heavy-duty diesel engines, flexible regulation of the heat release rate (HRR) profile combined with higher compression ratio could have more rooms to improve indicated thermal efficiency by overcoming various drawbacks relevant to higher compression ratio. A new ideal HRR profile, which starts as a kind of delta shape to fulfil the isobaric cycle from top-dead-center (TDC) and is followed by the significant increase in HRR to reach the maximum cylinder pressure in the retarded timing, was proposed. We call it as ‘High-heels’ HRR profile from its two-step-increase delta shape. To confirm the potential of the ideal HRR profile by utilizing a single- cylinder heavy-duty diesel engine, a variable fuel injection rate equipment, novel combustion chamber designs, and an offset orifices nozzle were investigated as the technologies for modifying HRR profile. The experimental results confirmed slight improvement in the thermal efficiency from the baseline, even though the maximum HRR in the late part of combustion and indicated thermal efficiency have not achieved the target with the integrated technologies yet.
Theoretical Calculation of Spray Deflection Angle of Direct-Injected Sprays from a Multiple-Orifice Nozzle
Authors: Fuyuto Takayuki
Published: November 2023

A theoretical calculation method for determining the deflection angle of direct-injection sprays injected from a multiple-orifice nozzle is developed by applying the extended spray momentum theory which takes the backward-flow surrounding sprays into account. The imbalance of the momentum of the backward gas flow causes a deflection of the sprays. The effect of the nozzle tip protrusion on the engine-out emissions of a diesel engine can be theoretically explained by the calculated deflection angles. Small variations in the nozzle tip protrusion are amplified at the rim of the piston cavity according to the spray deflection angle in the vicinity of the nozzle tip.
Calculation of spray collapse in multiple-hole gasoline direct injectors based on the spray momentum theory
Authors: Kataoka Hajime , Kojima Takayoshi , Yamashita Hayato , Okuma Masahiro , Fuyuto Takayuki
Published: November 2023

In this study, a new method to calculate the spray collapse in multiple-hole gasoline injectors was developed. The theoretical calculation method was proposed by applying the extended spray momentum theory. In this theoretical calculation method, the deflection of the spray direction toward the injector axis was calculated serially based on the imbalance of the momentum of backward gas-flow surrounding sprays. The calculation and spray observation for validation against the calculation result were performed under conditions with and without flash boiling.
Transient Flow Field Behavior after End of Spray Injection Under Different Injection and Flash Boiling Conditions
Authors: Zhou Ziming , Zhao Fengnian , Hung David L.S. , Li Xuesong , Xu Min
Published: November 2023

The continuous improvement of gasoline direct injection (GDI) engine is largely attributed to the enhanced understanding of air-fuel mixing and combustion processes. This work investigates the transient behavior of the ambient flow fields of hexane spray using the combined diagnostics of fluorescent particle image velocimetry (FPIV) and mie scattering. A hybrid analysis approach is proposed to investigate the residual effect of spray injection on ambient flow fields, including flow similarity measurement, entrainment velocity calculation, and vortex strength detection. The work investigates the residual effect under different injection durations, injection pressure, and flash-boiling extent of the spray, and unveils correlation between vortex strength and the endurance of the residual effect.
Effects of Different Driving Behavior during Actual Road Driving on Ammonia Emissions from Gasoline Vehicles
Authors: Sato Susumu , Chen Jiaxin , Eang Chanpaya , Tanaka Kotaro , Tange Takeshi
Published: November 2023

Three-way catalysts are used in gasoline vehicles for simultaneous purifying nitrogen oxide, carbon monoxide, and hydrocarbon in recent years. However, the reduction of ammonia emission generated in the three-way catalyst is pressing issue. In EURO 7, ammonia will also be subject to the Real Driving Emissions regulation, and its emissions must be reduced. Previous studies have shown that ammonia emissions are higher under fuel-rich conditions, suggesting that differences in driving behavior have a significant impact on ammonia emissions in real-world driving, which includes various driving environments. In this study, driving tests were conducted on a direct- injection gasoline vehicle equipped with a three-way catalyst and Portable Emission Measurement System and Sensor-based Emission Measurement System to investigate the actual ammonia emissions on actual roads. Sensor-based Emission Measurement System includes the system that can measure ammonia and nitrogen monoxide concentrations independently with high accuracy. Two drivers were used to analyze the effects of different driving behaviors on ammonia emissions. The results showed that ammonia emissions in real world driving largely affected by the lean-rich conditions of three-way catalyst and increased for the driver who drove more aggressively because he/she entered, and fuel cut conditions and the rich condition more frequently during deceleration and acceleration.
Visualization of Physical / Thermal Evaporation Phenomena with Experimental and PIV-DDM Analysis in Urea-SCR Dosing System of Multi-Phase Flow
Authors: NOHARA Tetsuo , SUGIYAMA Naoki , NARA Shotaro , ONO Jyo , ONOUE Hiroki , OSADA Rina , KAWAMOTO Yuki , OCHIAI Masayuki , TAKAHASHI Shun , OOSUMI Kazuo , ISHIKAWA Naoya
Published: November 2023

This study was visualized by experimental and numerical analysis for the unknown injected droplet phenomena with the multi-phase flow in the Urea-SCR dosing system. Visualization experiments were conducted on the droplet behavior inside the pipe with simulated urea SCR injection system. Although the total number of droplets decreases at gas temperatures of 150°C and 200°C, a significant number of injected droplets remained at the position corresponding to the SCR catalyst. That is physical kinetic energy was found to dominate over thermal evaporation. However, the impingement of droplets into the pipe wall had occurred complex behavior by physical/thermal evaporation, and these droplets weren't on gas airflow at the lower part of the pipe. Furthermore, these actual phenomena were reflected in experimental coefficients for new reduction model analysis instead of CFD.
Comparison on Combustion and Emissions Performance of Biodiesel and Diesel in a Heavy-duty Diesel Engine: NO
X
, Particulate Matter, and Particle Size Distribution
Authors: Cung Khanh , Buffaloe Gina , Michlberger Alex , Briggs Thomas , Bitsis Chris , Smith Edward , Khalek Imad
Published: November 2023

Low carbon emissions policies for the transportation sector have recently driven more interest in using low net-carbon fuels, including biodiesel. An internal combustion engine (ICE) can operate effectively using biodiesel while achieving lower engine-out emissions, such as soot, mostly thanks to oxygenate content in biodiesel.

This study selected a heavy-duty (HD) single-cylinder engine (SCE) platform to test biodiesel fuel blends with 20% and 100% biodiesel content by volume, referred to as B20, and B100. Test conditions include a parametric study of exhaust gas recirculating (EGR), and the start of injection (SOI) performed at low and high engine load operating points. In-cylinder pressure and engine-out emissions (NOX and soot) measurements were collected to compare diesel and biodiesel fuels. Exhaust particulate matter (PM) emissions were collected to assess solid particle mass and particle size distribution (PSD) using a micro-soot sensor (MSS) and a Cambustion different mobility spectrometer (DMS500), respectively.

Fuel consumption was higher with B20 and B100 than with diesel. However, soot emissions were reduced significantly with biodiesel fuels. B20 and B100 also have lower PSD curves, which indicates a smaller total particle count at a given mobility diameter (ranging from 6 nm to 1000 nm). PSD of all fuels shows a well- known bimodal characteristic. A slight difference in nitrogen oxides (NOX) emissions was observed and could be due to the difference in the physio-chemical properties of biodiesel and diesel fuels. Engine-out emissions of carbon monoxide (CO) and unburned hydrocarbon (UHC) are lower with biodiesel fuels than diesel.

High-speed combustion analysis suggests that minor modification in injection strategy is potentially needed for biodiesel fuels to deliver a diesel-like combustion profile, as seen by the apparent heat release rate (AHRR) curve. Overall, findings from current study suggest the drop-in capability in modern diesel engines of biodiesel with similar diesel-like efficiency and lower PM emissions.
An optimized, data-driven reaction mechanism for Dual-Fuel combustion of Ammonia and Diesel Primary Reference Fuels
Authors: Perini Federico , Reitz Rolf D. , Fiorini Niccolò , Innocenti Alessandro , Latinov Matteo , Vichi Giovanni
Published: November 2023

The possibility to operate current diesel engines in dual-fuel mode with the addition of an alternative fuel is fundamental to accelerate the energy transition to achieve carbon neutrality. The simulation of the dual- fuel combustion process with 0D/1D combustion models is fundamental for the performance prediction, but still particularly challenging, due to chemical interactions of the mixture.

The authors defined a novel data-driven workflow for the development of combustion reaction mechanisms and used it to generate a dual-fuel mechanism for Ammonia and Diesel Primary Reference Fuels (DPRF) suitable for efficient combustion simulations in heavy duty engines, with variable cetane number Diesel fuels.

A baseline reaction mechanism was created by merging the detailed ammonia mechanism by Glarborg et al. with reaction pathways for n- hexadecane and 2,2,4,4,6,8,8-heptamethylnonane from a well-established multi-component fuel mechanism. To define its target validity space, a standardized database of experimental measurements was developed which covers ignition delay times and species concentration profiles in shock tubes, rapid compression machines, and jet stirred reactors. Standardized experimental data served for both mechanism reduction, performance comparison of the optimized mechanism, and a source for simulation input. First, Element Flux (EF) Analysis was run to assess the activity coefficient of each species, and to define a set of reduced mechanisms; a 120-species, 1147 reactions was chosen as the target size and further optimized. During the genetic optimization, the reaction rates of the most relevant reactions were optimized, within uncertainty bounds gathered from the experimental literature. The merit function was evaluated as a multi-objective formulation that compared performance at all experiments.

The final mechanism showed noticeable accuracy improvements over the baseline “full” mechanism, with significantly smaller size. The generalized methodology also demonstrated successful mechanism development with little user input, and paved the way for further mechanism improvement and expansion to other target fuels.
Application of Argon Circulation to Investigate Fuel Nitrogen Oxides Emission Characteristics of Ammonia Spark Ignition Engines
Authors: Yang Ruomiao , Yan Yuchao , Ou Juan , Liu Zhentao , Liu Jinlong
Published: November 2023

Compared to fossil fuels, ammonia is an environmentally friendly, cost-effective, and readily available fuel that carries hydrogen. It is expected to play a crucial role in the development of carbon-neutral internal combustion engines for the next generation. However, a significant challenge arises due to the presence of nitrogen in both the fuel and air, leading to the complex generation of intertwined thermal and fuel-based nitrogen oxides (NOx) during ammonia combustion. To gain a deeper understanding of NOx emission characteristics and propose effective technologies for controlling NOx emissions from ammonia engines, it is essential to decouple the mechanisms responsible for thermal and fuel-based NOx and analyze the formation and evolution of both types separately. In this study, a novel approach employing argon circulation is applied to eliminate the thermal NOx formation mechanism. This allows for a detailed investigation of fuel-based NOx emissions in ammonia spark ignition engines. The results reveal that nitric oxide (NO) species still dominates, accounting for over 98% of the fuel NOx emissions under the investigated conditions. Furthermore, fuel NOx exhibits distinct concentration distribution patterns within the combustion chamber and displays a different relationship with engine control variables compared to thermal NOx. Specifically, fuel-based NOx is likely produced as a by-product of chemical equilibrium calculations within the flame front, with subsequent evolution within the burned zone. Moreover, fuel-based NOx increases with delayed spark timing, in contrast to the trend observed for thermal NOx. Lean operation favors fuel NOx formation, although excessively lean operation reduces NOx due to a lower nitrogen content in the fuel-oxidizer mixture. On the other hand, rich operation prevents NOx formation because of the ammonia’s de-NOx effect. The emissions of nitrous oxide (N2O) in the exhaust gases primarily originate from newly formed N2O during the late oxidation stage. Of these N2O, a portion of N2O is formed close to the cold walls, and another portion results from the partial oxidation of ammonia released from the crevice volume, where ammonia is trapped during the primary combustion stage. Lean operation promotes N2O formation and should be avoided to minimize its emissions. In conclusion, the implementation of the argon circulation system successfully elucidates the characteristics of fuel NOx formation in engines, which have been fully addressed in previous discussions. Moreover, this approach can also be extended to other engine types, such as ammonia-methane spark ignition engines, ammonia-hydrogen spark ignition engines, and compression ignition engines converted to ammonia-diesel dual-fuel engines.
The Fuel Economy Improvement Effect of MoDTC with Low Viscosity Engine Oil under Hybrid Electric Vehicle
Authors: Takano Koichi , Iino Shinji , Yamamoto Kenji , Moriizumi Yukiya
Published: November 2023

In order to confirm friction and fuel economy performance of engine oils, laboratory bench tests, motored engine tests and chassis dynamo tests with HEV under WLTP were conducted. The fuel economy improvement effect of reducing viscosity and MoDTC were confirmed under these tests. Moreover, MoDTC (std.) exhibited excellent fuel economy improvement effect compared to MoDTC (L) under low temperature condition particularly. Low viscosity oils formulated with MoDTC (std.) showed superior fuel economy performance even at HEV with relatively lower oil temperatures in this study.
Investigating the morphology and nanostructure of carbon black dispersed in lubricant oils and their impact on chain wear as a proxy of marginally lubricated components
Authors: Pacino A. , La Rocca A. , Kirkby T. , Reddyhoff T. , Cairns A. , Smith J. , Berryman J. , Fowell M.
Published: November 2023

Excessive soot concentration in the lubricant promotes excessive wear on timing chains. The relationship between chain wear and soot concentration, morphology, and nanostructure, however, remains inconclusive. In this work, a chain wear test rig is used to motor a 1.3 L diesel engine following the speed profile of a Worldwide Harmonized Light Vehicle Test Cycle (WLTC). The lubricant oil was loaded with 3% carbon black of known morphology. The chain length is measured at regular intervals of 20 WLTC cycles (i.e. 10 hours) and the wear is expressed as a percentage of total elongation. Oil samples were collected and analysed with the same frequency as the chain measurements. Carbon black morphology and nanostructure were investigated using Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). DLS data revealed carbon black particle size did not change substantially in the first 10 hours, however, during the remaining test cycles a reduction in agglomerates size over time was observed. The wear results show that adding carbon black to the lubricating oil promotes chain elongation by up to 0.10%. Significant chain elongation occurred within the first 10 hours (+0.06%), with further increase in elongation occurring in the remaining 40 hours (+0.04%) but under a reduced wear rate. The overall results suggest that dynamically changing carbon black size distributions and nanostructure could be linked changes over time.
Advanced Rapid Combustion Concept Using Autoignition Assisted Flame for High Compression Ratio SI Engines
Authors: Sasaki Yuta , Hori Junki , Seto Masatoshi , Fujikawa Tatsuya , Morii Youhi , Nakamura Hisashi , Maruta Kaoru
Published: November 2023

To achieve higher thermal efficiency for spark- ignition (SI) engines, advanced rapid combustion technology under high compression ratio is needed. The results of single-cylinder preliminary engine tests using E.U. commercial fuel at 96 RON show that the higher the compression ratio, the faster the combustion speed. Additional engine test and computations using S5R five-component surrogate gasoline with reliable chemistry under various temperature and pressure conditions implied that the autoignition assisted flame played significant role under higher compression ratio conditions, i.e., high temperature and pressure conditions, where apparent increases in laminar flame speeds compared to conventional combustion.
Development of Detailed Surface Reaction Mechanism of CO/ NO/ O2 System for Three Way Catalyst Based on Gaseous and Surface Species Analyses
Authors: Matsumoto Yuhei , Shimokuri Daisuke , Miyoshi Akira , Hinokuma Satoshi , Murakami Hiroshi , Kawano Michiharu
Published: November 2023

In this study, we determined the detailed reaction mechanism of CO/NO/O2 for automotive three way catalysts. The N2O formation process obtained from measurements of the reaction properties and the formation process of adsorbed NCO species obtained from surface analysis of platinum group metals were added to a previous detailed surface reaction mechanism. The computational accuracy of the developed reaction mechanism was verified by the one-dimensional simulation software BOOST, and it was found to be sufficient for any combination of platinum group metals and gas concentrations.
Investigation of Exhaust Particles on Different TEM Grids: a Comparison between Graphene Oxide and Silicon Nitride Grids
Authors: Lagana Salvatore , Akifjevs Romans , Rocca Antonino La , Cairns Alasdair , Fay Michael W. , Webb Kevin F.
Published: November 2023

Two different TEM (Transmission Electron Microscopy) grids - graphene oxide (GO) and silicon nitride (SiN) - were used to capture the particulates emitted with the exhaust of a modern 1.0 L GDI (Gasoline Direct Injection) engine. One speed-load condition (1250 rpm – idle) was chosen to generate a nanometric particulate output in the sub-23 nm regime which has been traditionally difficult to analyse in terms of composition and morphology. The overall aim was to understand if additional benefits can be obtained by analysing the particles captured in the exhaust on a nanoporous silicon nitride grid compared to state-of- the-art graphene oxide grids. The behaviour of porous SiN support films was of interest since nanopores are present in the grid in the 20 nm regime and the material is thermally and dimensionally stable under high temperatures, allowing thermophoretic capture directly within the engine exhaust stream. In addition to nanostructural and morphological comparison, the elemental composition of the particles was also analysed by EDX (Energy Dispersive X-Ray). Particles were thermophoretically captured directly in the exhaust stream using a dedicated probe holding the grid. Because of their tiny 2 nm thickness, GO grids work well for studying particle nanostructure, however background noise from copper and carbon interferes with compositional analysis by EDX. In contrast, the silicon nitride grids enable particle observation without this background noise, providing an intriguing platform for the analysis of the suspended particles collected by the pores. Future research will concentrate on producing particles with graphitic areas to assess imaging advantages in terms of morphological and nanostructural examination. The two grids were similar in their particle capture within the engine, with close mean primary particle diameters using both: 13.5 ± 3.1 nm standard deviation (SD) on GO and 14.1 ± 2.6 nm SD on SiN. EDX analysis suggests SiN grids, as C-free substrates, are preferable to GO for determining the carbon load in captured particles. This investigation is part of a larger project focusing on decarbonised fuels, so a carbon-free support film is pivotal in understanding the nature and composition of the fine particles linked to the lubricant oil.
A study of Multi-Functional Membrane Filters made of Fine Catalyst Particles
Authors: Hanamura Katsunori , Fujii Shinpei , Teerapat Suteerapongpun
Published: November 2023

A multi-functional membrane filter was developed through deposition of agglomerated Three-Way Catalyst particles with a size of 1 ~ 2 microns on the conventional bare particulate filter. The filtration efficiency reaches almost 100 % from the beginning of soot trapping with a low pressure drop and both reductions of NO and CO emission were achieved.
Waste Plastic Pyrolytic Oil Blends as Valuable Fuels for Modern Compression Ignition Engines
Authors: Hunicz Jacek , Rybak Arkadiusz , Duda Kamil , Sivalingam Murugan , Mikulski Maciej
Published: November 2023

This study tests the use of thoroughly-evaluated waste plastic pyrolytic oils (WPOs) as substitute fuels in a modern, single-cylinder, diesel research engine. Emissions results are supported by FTIR analysis of exhaust gases, identifying 20 species. The results show that contemporary Tier 4-compliant combustion systems with split injection can handle high polypropylene-based WPO content in diesel fuel without re-calibration. Combustion phasing is delayed only at near-idle loads. Hydrocarbon and CO emissions are elevated, but to an acceptable extent. Engine fueling with high admixtures of polystyrene- based WPO results in unstable combustion at low loads and emission issues across the whole load range.
Evaluation and Analysis of Hydrogen Embrittlement Characteristics of Various Steel Materials
Authors: Suzuki Ryoji , Matsume Yuri , Katori Noriaki
Published: November 2023

Austenitic stainless JIS SUS316L (16Cr–12Ni–2Mo) steel equivalent material that offers excellent hydrogen embrittlement resistance is used for the high pressure hydrogen pathways in FCEVs. However, there is a need to switch to less expensive material. This paper proposes a technique to evaluate hydrogen embrittlement simulated in high-pressure hydrogen environments based on the use of cathode charging and slow strain rate testing (SSRT) at atmospheric pressure, while also providing an analysis of the hydrogen embrittlement mechanism. At the same time, it presents an evaluation of hydrogen embrittlement resistance of ferrite material, a candidate low-cost material.
Demonstration Test of Automotive Photovoltaic System for an Electric Vehicle
Authors: Tomita Yosuke , Tanimoto Tsutomu , Saito Masanori , Nagai Yoshiyuki , Arai Takumi , Nishijima Kimihiro
Published: November 2023

A high-power photovoltaic (PV) system for an electric vehicle was fabricated. The total rated power of the PV panels was 1150 W. A demonstration test was conducted for a year. The test data showed that the prototype PV system was able to generate energy equivalent to approximately 7,100 km/year in driving distance. It was also found that if the vehicle is used for commuting about 10 km one way, it is mostly not necessary to recharge the vehicle from the grid throughout the year. In addition, the system was able to maintain maximum power point tracking (MPPT) control during driving even when the solar radiation changed frequently.
An experimental study to assess the impact of discharge frequency of the dielectric barrier discharge on ignition process of premixed mixture under elevated pressure
Authors: AGRAWAL Saurabh , YAMAMOTO Shuya , HORIBE Naoto , HAYASHI, Jun , KAWANABE Hiroshi
Published: November 2023

To understand the effect of discharge frequency and discharge energy of dielectric barrier discharges (DBD) on the flame kernel development process, the observation of the discharges and ignition trials were performed in a constant volume vessel. Results showed that the energy of DBD released during a single cycle of discharge decreases, but the power of the discharges increases with the frequency increases. The ignition probability improved and the time for the flame propagation decreased under high frequency because the power of the discharges efficiently rises the local gas temperature near the electrodes.