Browse Topic: Diesel / compression ignition engines

Items (11,311)

Impact of Chemical Poisoning and Hydrothermal Aging on a Production Diesel AT System

2025-01-8497

04/01/2025

Diesel aftertreatment (AT) systems are critical for controlling emissions of CO, HC, NOX, and PM in the on-road transportation sector. Ensuring compliance with regulatory standards throughout the AT system's lifespan requires precise prediction of various degradation mechanisms under real-world operating conditions and mitigating their impact through proper catalyst sizing and advanced controls. In the SwRI A2CAT-II consortium, a medium-duty diesel engine production aftertreatment system was subjected to full useful life aging, involving chemical poisoning with phosphorus (P) and sulfur (S) species, along with hydrothermal aging following the DAAAC protocol. This study was aimed to model and predict the aging trajectory of this production AT system thereby capturing changes in system dynamics under both steady-state and transient conditions. The system, designed to meet the 0.2 g/bhp-hr standard, comprised a Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective

Balakrishnan, Arun, Chundru, Venkata Rajesh, Eakle, Scott, Sharp, Christopher

3D CFD Analysis of Predicting Engine Blowby Considering Ring Dynamics

2025-01-8622

04/01/2025

This paper reports on the development of a simulation model to predict engine blowby flow rates for a common rail DI diesel engine. The model is a transient, three-dimensional computational fluid dynamics (CFD) model. Managing blowby flow rates is beneficial for managing fuel economy and oil consumption. In doing so, an improved understanding of the blowby phenomenon is also possible. A mesh for the sub-micron level clearances (up to 0.5 microns) within the piston ring pack is created using a novel approach. Commercial CFD software is used to solve the pressure, velocity, and temperature distributions within the fluid domain. Ring motions within the piston grooves are predicted by a rigorous force balance. This model is the first of its kind for predicting engine blowby using a three-dimensional simulation model while solving the complete set of governing transport equations, without neglecting any terms in the equations. The predicted blowby flow rate has been validated with

Manne, Venkata Harish Babu, Bedekar, Sanjeev, Srinivasan, Chiranth, Das, Debasis, Ranganathan, Raj

Effect of Fuels on Compression Ignition Engine Particle Size Distribution and DPF Filtration Efficiency

2025-01-8503

04/01/2025

A diesel engine was run on off-highway cycle sequence on nine (9) fuels and blends. Number-weighted solid particle size distribution (PSD) in the size range from 5.6 nm to 560 nm was measured at inlet and outlet of a diesel particulate filter (DPF) on a sequence of five (5) non-road transient cycles (NRTCs) and five (5) non-road steady-state cycles (NRSCs). The measurements were used to correlate the fuel properties to the DPF-In concentrations and filtration of different size particles in the DPFs. The data showed an expected trend with the DPF-In emissions. Ultra-low sulfur diesel (ULSD) had the highest solid particle number (SPN) concentrations and biodiesels (soy-based biodiesel (B100) and rapeseed-based biodiesel (RME)) had the lowest concentrations. The geometric number mean diameter (GNMD) of DPF-In PSD correlates with the concentrations. The calculated GNMD was the highest for ULSD and lowest for B100/RME. An opposite trend for the GNMD was observed at the DPF-Out where the

Lakkireddy, Venkata, Khalek, Imad, Buffaloe, Gina

Effects of Post-Injection Strategy on the Performance of Diesel Catalyst-Heating Operation

2025-01-8414

04/01/2025

Minimizing the time needed to achieve light-off temperatures in diesel engine aftertreatment devices is key to mitigate pollutant emissions during the first minutes of operation. Catalyst heating operation typically includes one or multiple post-injections late during the expansion stroke aimed to increase the enthalpy of the exhaust gases. However, post-injection retardability is constrained by low combustion efficiency and the formation of CO and unburned hydrocarbons that cannot be oxidized by a still-inactive oxidation catalyst. In this study, the effects of post-injection strategy on the performance and emissions of a medium duty diesel engine have been investigated experimentally, focusing on the impacts on post-injection retardability. A five injection strategy (two pilot, one main, two post) was implemented in the engine, and the injection duration ratio between the two post-injections has been varied systematically while performing post-injection timing sweeps to identify the

Lopez Pintor, Dario, Lee, Sanguk, Cho, Seokwon, Busch, Stephen, Wu, Angela, Narayanan, Abhinandhan, Abboud, Rami

Achieving Ultra-Low NO _x and Meeting Full Useful Life Requirement for CARB 2027 NO _x and GHG 2027 Phase 2 CO ₂ Regulation w/Opposed Piston 2-Stroke Engine and a Conventional ATS

2025-01-8391

04/01/2025

Internal combustion engines are expected to continue to play an important on-going role in the future of transportation, particularly in long haul transit and off-road applications. Substantially reducing criteria emissions of heavy-duty (HD) commercial vehicle engines while also reducing fuel consumption is the quickest way to achieve more sustainable transportation. The opposed-piston (OP) engine developed by Achates Power has demonstrated the ability to meet the most stringent ultralow NOx emissions requirements using only a conventional, underfloor aftertreatment system, offering reduced cost, complexity and compliance risk compared to other diesel engines. This paper is focused on the measurement results of Achates Power heavy-duty engine achieving CARB proposed ultralow NOx emission for 2027 and 2031+ full useful life requirements while also meeting the EPA Greenhouse Gas (GHG) Phase 2 limits with a conventional aftertreatment system (ATS), which was aged to 435k, 600k and 800k

Kale, Vaibhav, Bako, Zoltan

Combustion and Emission Performance from the Use of Acid-Catalysed Butanol Alcoholysis Derived Advanced Biofuel Blends in a Compression Ignition Engine

2025-01-8445

04/01/2025

Low-carbon alternatives to diesel are needed to reduce the carbon intensity of the transport, agriculture, and off-grid power generation sectors, where compression ignition (CI) engines are commonly used. Acid-catalysed alcoholysis produces a potentially tailorable low-carbon advanced biofuel blend comprised of mixtures of an alkyl levulinate, a dialkyl ether, and the starting alcohol. In this study, model mixtures based on products expected from the use of n-butanol (butyl-based blends) as a starting alcohol, were blended with diesel and tested in a Yanmar L100V single-cylinder CI engine. Blends were formulated to meet the flash point, density, and kinematic viscosity limits of fuel standards for diesel, the 2022 version of BS 2869 (off-road). No changes to the engine set-up were made, hence testing the biofuel blends for their potential as “drop-in” fuels. Changes in engine performance and emissions were determined for a range of diesel/biofuel blends and compared to a pure diesel

Wiseman, Scott, Li, Hu, Tomlin, Alison S.

Development of Ultra-Fast AI-Driven Diesel Engine Model for Real-Time Optimization

2025-01-8397

04/01/2025

Combustion engines and hybrid systems remain important in sectors like light- and heavy-duty vehicles, where performance, range, or cost limitations play a major role. Optimizing diesel engine efficiency and reducing emissions is critical. However, classical physics-based 0D/1D models are computationally demanding and are hardly applicable for real-time purposes. In this study, a calibrated 1D diesel engine model is suggested for transformation into a neural network architecture to enable real-time optimization. The model divides the engine into intake, exhaust, and combustion sections, each modeled by different neural networks. One of the advantages of this modular and layered approach is the flexibility to change individual components without needing to retrain every single model. Long Short-Term Memory (LSTM) networks are used to capture transient phenomena, such as thermal inertias that arise in the combustion process and gas flow dynamics. The training data was generated by

Frey, Markus, Itzen, Dirk, Sautter, Johannes, Weller, Louis, Hagenbucher, Timo, Yang, Qirui, Grill, Michael, Kulzer, Andre Casal

Comprehensive Prediction of Deposit Formation in SCR Systems Using Integrated 1D Heat Transfer Model with Empirical Data from 3D CFD Simulations

2025-01-8491

04/01/2025

Urea-based selective catalytic reduction (SCR) systems are widely used to meet stringent NOx emission standards in industrial diesel engines. However, suboptimal design of the urea-water solution (UWS) mixing pipes in SCR systems can lead to the formation of urea-derived solid deposits, which may adversely affect the system performance and reliability. Although recent advancements in deposit simulation technology using three-dimensional Computational Fluid Dynamics (3D CFD) have significantly improved the performance and compactness of mixing pipes, assessing deposit formation across all operating and environmental conditions remains challenging due to high simulation costs. This study introduces a novel computational method for predicting the formation and temperature of permanent liquid films from UWS injection which are closely related to deposit formation, along with new deposit evaluation criteria based on them. This proposed method integrates a one-dimensional heat transfer model

Sugimoto, Kazuma, Kawabe, Ken

Spray Characterization in a Constant Volume Chamber of Aluminum Oxide Nanoparticles-Diesel Blends

2025-01-8455

04/01/2025

Aluminum oxide (Al₂O₃) nanoparticles are considered a promising fuel additive to enhance combustion efficiency, reduce emissions, and improve fuel economy. This study investigates the spray characteristics of diesel fuel blended with aluminum oxide nanoparticles in a constant volume chamber. The blends were prepared by dispersing Al₂O₃ nanoparticles in diesel at varying concentrations (25, 50, and 100 mg of aluminum oxide nanoparticles into 1 L of pure diesel, respectively) using a magnetic stirrer and ultrasonication to ensure stable suspensions. Spray characterization was conducted in a high-pressure and high-temperature constant volume chamber, simulating actual engine conditions. The ambient temperatures for this experiment were set from 800 to 1200 K, and the oxygen concentrations were set from 21% to 13%. The study focused on key spray parameters such as spray penetration length, spray angle, and spray area, analyzed using high-speed imaging and laser diffraction techniques

Ji, Huangchang, Zhao, Zhiyu

Experimental Analysis of Piston Surface Temperature in a Heavy-Duty Compression Ignition Engine

2025-01-8383

04/01/2025

The heat transfer processes occurring in a compression ignition engine are complex, especially considering flame-wall interaction on the piston crown from impinging jets. To study the heat flux occurring on the piston in a heavy-duty diesel engine, a piston was instrumented with fifteen thermocouples and a wireless telemetry system. Eight of the thermocouples are high speed surface thermocouples placed primarily in regions with significant flame-wall interaction, providing crank-resolved surface temperature data. This work presents the first experimental datasets collected with this instrumented piston, describing in detail the thermocouple location selection process as well as data processing and uncertainty quantification for the high-speed surface thermocouples with a particular emphasis on cyclic variability and sensor-to-sensor variability. With this methodology established, data from this piston can be used for modeling and simulation studies as well as for studying the impact of

Gainey, Brian, Datar, Aditya, Ravikumar, Avinash, Bhatt, Ankur, Vedpathak, Kunal, Kumar, Mohit, Gingrich, Eric, Tess, Michael, Korivi, Vamshi, Lawler, Benjamin

Achieving Lagrangian-esque Fuel Mass Tracking in an Eulerian Frame of Reference CFD Diesel Engine Simulation

2025-01-8358

04/01/2025

Diesel combustion is a highly heterogeneous process in which the fuel must undergo several sub-processes after injection in order to release its heat through combustion. Prior to evaporation, computational fluid dynamic (CFD) simulations track the injected fuel mass using a Lagrangian frame of reference to determine the pathlines of the liquid fuel in the gaseous environment. However, after evaporation, when the fuel mass becomes part of the working fluid, it is no longer tracked in a Lagrangian reference frame as it undergoes its mixing and combustion processes. To gain deeper insights into the diesel combustion process, a methodology is proposed to track the evolution of fuel mass packets while in the gaseous state attaining a Lagrangian-esque description of the fuel’s evolution. This is achieved using the commercially available capabilities in Convergent Science’s CFD package, without requiring user-defined functions. The methodology is applied to a heavy-duty diesel engine and

Gohn, James, Kumar, Mohit, Gainey, Brian, Lawler, Benjamin

Efficient Modeling of SCR Urea Deposits Formation Using ANSYS Fluent

2025-01-8485

04/01/2025

This paper presents recent developments of the Euler/Lagrange wall film model which allow the efficient simulation of complete Selective Catalytic Reduction (SCR) systems, used for exhaust gas aftertreatment in diesel and newly designed H2 engines. Since release 2024R2, ANSYS Fluent is equipped with a chemistry model from recent literature to predict homogeneous chemical reactions in the film and heterogeneous reactions between gas and film occurring in SCR systems operating with aqueous urea solutions. The implementation of the chemistry model is first validated against results from Thermo–Gravimetric Analysis (TGA) measurements. The SCR–specific chemistry, combined with the Lagrangian Wall Film (LWF) model employing an improved wall–film convective heat transfer model, is then compared favorably with experimental SCR test rig measurements of urea deposits for fifty injection cycles, followed by a relaxation period. The full simulation completes significantly faster due to a new

Sofialidis, Dimitrios, Mutyal, Jayesh, Faltsi, Rana, Braun, Markus, Börnhorst, Marion, Esch, Thomas

Data-driven Modeling and Control Framework for Multi-Fuel Compression-Ignition Engines

2025-01-8349

04/01/2025

Controlling the combustion phasing of a multi-fuel compression ignition engine in varying ambient conditions, such as low temperature and pressure, is a challenging problem. Traditionally, engine control is achieved by performing experiments on the engine and building calibration maps. As the number of operating conditions increase, this becomes an arduous task, and model-based controllers have been used to overcome this challenge. While high-fidelity models accurately describe the combustion characteristics of an engine, their complexity limits their direct use for controller development. In recent years, data-driven models have gained much attention due to the available computation power and ease of model development. The accuracy of the developed models, which, in turn, dictates the controller’s performance, depends on the dataset used for building them. Several actuators are required to achieve reliable combustion across different operating conditions, and obtaining extensive

Govind Raju, Sathya Aswath, Sun, Zongxuan, Kim, Kenneth, Kweon, Chol-Bum

A Conjugate Heat Transfer Numerical Framework Applied to Energy-Assisted Ignition of Jet Fuel in a Rapid Compression Machine

2025-01-8352

04/01/2025

Airborne compression ignition engines operating with aviation fuels are a promising option for reducing fuel consumption and increasing the range of hybrid-electric aircraft. However, the consistent ignition of Jet fuels at high-altitude conditions can be challenging. A potential solution to this problem is to ignite the fuel sprays by means of a glow-plug-based ignition assistant (IA) device. The interaction between the IA and the spray, and the subsequent combustion event result in thermal cycles that can significantly affect the IA’s durability. Therefore, designing an efficient and durable IA requires detailed understanding of the influence that the IA temperature and insertion depth have on the complex physics of fuel-air mixture ignition and flame propagation. The objective of this study is to design a conjugate heat transfer (CHT) modeling framework that can numerically replicate F-24 Jet fuel spray ignition using a glow-plug-based IA device in a rapid compression machine (RCM

Oruganti, Surya Kaundinya, Lien, Hao-Pin, Torelli, Roberto, Motily, Austen, Lee, Tonghun, Kim, Kenneth, Mayhew, Eric, Kweon, Chol-Bum

Formation and Decomposition of Ammonium Sulfate Species over a Small Pore Cu/Zeolite Catalyst

2025-01-8493

04/01/2025

Cu/zeolite selective catalytic reduction (SCR) catalysts are used globally to reduce NOx emissions from diesel engines. These catalysts can achieve high NOx conversion efficiency, and they are hydrothermally durable under real world diesel exhaust environments. However, Cu/zeolite catalysts are susceptible to sulfur poisoning and require some type of sulfur management even when used with ultra-low sulfur diesel (ULSD). In the present study, the authors seek to better illuminate the chemical processes responsible for ammonium sulfate formation and decomposition occurring in Cu/zeolite SCR catalysts. Reactor-based experiments are first conducted with a real-world concentration of SO2 (0.5 ppmv) and a typical diesel exhaust water vapor concentration (7 vol.%) to quantify progressive effects of ammonium sulfate formation. A second group of experiments probe the chemical decomposition of ammonium sulfate via NO titration. The “movement” of sulfate species during this process is monitored

Ottinger, Nathan, Xi, Yuanzhou, Liu, Z. Gerald

Ammonia-Hydrogen Combustion in a Heavy-Duty Diesel Engine Converted to Spark Ignition Operation

2025-01-8448

04/01/2025

Ammonia is a carbon-free fuel alternative for the internal combustion engine decarbonization. However, its toxicity and less advantageous combustion characteristics including higher nitrogen-based engine-out emissions have delayed its use in power generation applications. Therefore, the use of a secondary and also carbon-free fuel such as hydrogen was proposed in the literature as a solution to promote and improve ammonia combustion while minimizing any modifications in engine parameters and control strategy that may be required when compared to using conventional hydrocarbon-based fuels. In addition, the higher resistance to autoignition of ammonia can allow operation at higher compression ratios in spark ignition applications, therefore increasing the thermal efficiency. The study presented here used a single-cylinder heavy-duty research engine converted to spark ignition operation to investigate medium load engine operation with ammonia-hydrogen blends in which hydrogen represented

Alvarez, Luis, Saenz Prado, Stefany, Trujillo Grisales, Juan, Dumitrescu, Cosmin

Investigation of Dimethyl Ether Injection Profiles in High-Pressure Direct Injection System

2025-01-8464

04/01/2025

The majority of transportation systems continue to rely on internal combustion engines powered by fossil fuels. Heavy-duty applications, in particular, depend on diesel engines due to their high brake efficiency, power density, and robustness. Despite significant advancements in diesel engine technology that have reduced emissions and improved efficiency, complex and costly after-treatment systems remain necessary to meet the stringent emission regulations. Dimethyl ether (DME), which can be produced from various renewable feedstocks and possesses high chemical reactivity, is a promising alternative for heavy-duty applications, particularly in compression ignition direct injection engines. Its high reactivity, volatility, and oxygenated composition offer significant potential to address emission challenges while reducing reliance on after-treatment systems. However, DME’s lower energy density requires adjustments in injection parameters (such as injection pressure and duration) or

Cong, Binghao, Leblanc, Simon, Tjong, Jimi, Ting, David, Yu, Xiao, Zheng, Ming

Virtual Evaluation of Ceramic Glow Plug Design using Multiphysics Simulation Approach

2025-01-8367

04/01/2025

A glow plug is generally used to assist the starting of diesel engines in cold weather condition. Low ambient temperature makes the starting of diesel engine difficult because the engine block acts as a heat sink by absorbing the heat of compression. Hence, the air-fuel mixture at the combustion chamber is not capable of self-ignition based on air compression only. Diesel engines do not need any starting aid in general but in such scenarios, glow plug ensures reliable starting in all weather conditions. Glow plug is actually a heating device with high electrical resistance, which heats up rapidly when electrified. The high surface temperature of glow plug generates a heat flux and helps in igniting the fuel even when the engine is insufficiently hot for normal operation. Durability concerns have been observed in ceramic glow plugs during testing phases because of crack formation. Root cause analysis is performed in this study to understand the probable reasons behind cracking of the

Karmakar, Nilankan, Orban, Hatem

Three-Body Abrasive Wear Surface Characterization of Military Diesel Engine Piston Rings and Cylinder Bores

2025-01-8346

04/01/2025

Two 50-hr engine dynamometer tests were conducted on 12-cylinder diesel military engines with differing piston ring sets. Engine A exhibited more than double the oil consumption over engine B. An investigation was conducted to explain why the oil consumption differed by employing several posttest analytical techniques including cylinder bore geometry measurements, surface metrology, wear characterization, and chemical analysis on the piston rings and cylinder wall coatings. The 3D colormaps of cylinder bore deformation showed uneven volumetric deformation through the piston stroke instead of 2D plane deformation. It was found that the primary reason of high oil consumption was direct loss of sealing between the piston, piston ring and cylinder bore due to predominately abrasive wear, three-body abrasive wear and bore polishing. Furthermore, the compromised sealing of the combustion chamber led to blow-by. Carbon deposits, corrosive byproducts, surface abrasives, loss of desired surface

Thrush, Steven, Chen, Aijie, Foley, Michael, Sebeck, Katherine, Boufakhreddine, Ziad

Fuel Composition Effects on Combustion Characteristics of a Low-Temperature Gasoline Combustion Engine

2025-01-8410

04/01/2025

Low Temperature Gasoline Combustion (LTGC) in compression ignition engines is controlled by chemical kinetics and the autoignition reactivity of the fuel-air mixture, which are heavily influenced by the composition of the fuel. To investigate fuel-engine interactions, experiments were performed on a single-cylinder LTGC engine at various operating conditions with three premium-grade gasoline-like fuels with nominally the same octane rating but with high aromatic (HA), high cycloalkane (HCA) and high ethanol (E30 - 30%vol) contents, respectively. At fully-premixed naturally aspirated conditions, E30 showed the highest autoignition reactivity followed by HCA and HA. However, reactivity differences became less relevant when direct-injecting the fuel because of the vaporization cooling effect on the in-cylinder reactivity, which compensated for differences in fuel’s chemistry. Intake pressure sweeps demonstrated that the autoignition reactivity of E30 had the highest sensitivity to

Narayanan, Abhinandhan, MacDonald, James, Lee, Sanguk, Lopez Pintor, Dario

Control-Oriented Statistical Model of In-Cylinder Pressure, Combustion Phasing, and Torque for Compression-Ignition Engines Operating with Low Cetane Fuels

2025-01-8351

04/01/2025

Sustainable aviation fuels are becoming more widely available for current and future engine powered propulsion systems. However, the diversity of ignition behavior in these fuels poses a challenge to achieving robust, efficient operation. Specifically, low cetane fuels with poor ignitability exhibit highly variable torque production unless fuel is injected earlier during compression. The tradeoff is that earlier injection may cause dangerously high in-cylinder pressure rise rates. Novel models that can simulate these competing behaviors are needed so that appropriate strategies may be developed for controlling combustion at low cetane fueling conditions. This work builds upon a previously developed model that simulates asymmetric combustion phasing (CA50) distributions as a function of fuel cetane, fuel injection timing, and electrical power supplied to an in-cylinder thermal ignition assist device. An extension of the model is presented in which the phasing output is used to

Ahmed, Omar, Middleton, Robert, Stefanopoulou, Anna, Kim, Kenneth, Kweon, Chol-Bum

Decarbonization of Off-Road Engines by Methanol Mixing-Controlled Compression Ignition with Ignition Enhancer

2025-01-8411

04/01/2025

Methanol is one of the most promising fuels for the decarbonization of the off-road and transportation sectors. Although methanol is typically considered an alternative fuel for spark ignition engines, mixing-controlled compression ignition (MCCI) combustion is typically preferred in most off-road and medium-and heavy-duty applications due to its high reliability, durability and high-efficiency. In this paper, methanol MCCI combustion was enabled using ignition improvers and the potential benefits of this approach compared to conventional diesel combustion were investigated. Methanol was blended with 7%vol of 2-ethylhexyl nitrate (EHN) and experiments were performed in a single-cylinder production-like diesel engine with a displacement volume of 0.8315 L and a compression ratio of 16.5:1. The conditions of the ISO 8178 C1 regulatory cycle for off-road engines were tested, and performance and emissions over the cycle were calculated. Methanol MCCI shows 5.3% lower fuel consumption (in

Lee, Sanguk, Lopez Pintor, Dario, MacDonald, James, Narayanan, Abhinandhan, Chan, Adrian

Performance and Emissions Analysis of a Hydrogen-Powered Heavy-Duty High Compression Ratio SI Engine Across Various Loads and Speed at Ultra-Lean Condition

2025-01-8428

04/01/2025

With the global shift towards sustainable and low-emission transportation, hydrogen-fueled engines stand out as a promising alternative to traditional fossil fuels, offering significant potential to reduce greenhouse gas emissions. This study provides a comprehensive evaluation of the performance and emissions characteristics of a hydrogen-powered heavy-duty compression ignition engine, which has been modified to operate as a Spark Ignition (SI) engine with a high compression ratio of 17:1. The evaluation was conducted across various speeds, loads, and spark timings under ultra-lean combustion conditions. The analysis utilized a modified 6-cylinder, 13-liter Volvo D13 diesel engine, configured to operate in single-cylinder mode with the addition of a spark plug for SI operation. The study examined key performance metrics, including brake thermal efficiency (BTE), power output, and specific fuel consumption, under the selected operating conditions. Emissions profiles for nitrogen oxides

Dyuisenakhmetov, Aibolat, Panithasan, Mebin Samuel, Cenker, Emre, AlRamadan, Abdullah, Im, Hong, Turner, James

Effect of Fuels on Compression Ignition Engine Particle Number and Mass Emissions and DPF Filtration Efficiency

2025-01-8502

04/01/2025

As part of decarbonization, alternative fuels are likely to be used in compression ignition internal combustion engines as a substitute for diesel fuel. There have been many studies on the effect of these alternative fuels on emissions and catalytic aftertreatment systems. Past research has reported lower particulate matter (PM) and higher oxides of nitrogen (NOx) with biofuels. However, there are limited studies on the effect of PM on the performance of diesel particulate filters (DPFs), especially in its effectiveness of PM filtration. PM emissions from four (4) types of fuels and five (5) of their blends, a total of nine fuels, were investigated using PM2.5 mass, soot mass, solid particle number (> 10 nm SPN10 and > 23 nm SPN23) and size distribution (6 nm to 560 nm) measurements at inlet and outlet of a DPF. The PM emissions were measured over a non-road regulatory cycle sequence consisting of five (5) non-road transient cycles (NRTCs) and five (5) non-road steady-state cycles

Lakkireddy, Venkata, Khalek, Imad, Buffaloe, Gina

Combustion Characterization and Heat Release Rate Modeling of a Heavy-Duty Hydrogen-Diesel Dual-Fuel Engine

2025-01-8418

04/01/2025

Introducing hydrogen (H2) into the intake air of diesel engines provides a near-term approach to reducing tailpipe CO2 emissions from heavy-duty commercial vehicles. The premixed hydrogen results in a complex H2-Diesel dual fuel (H2DF) combustion process, where H2 can both participate in the non-premixed diesel combustion and result in a propagating H2/air combustion. These interactions influence engine combustion characteristics, including in-cylinder pressure and heat release rate (HRR), as well as emissions. The nature and extent of the impact depends on the amount of H2 introduced as a function of the total fuel energy (H2 energy share ratio - HES), the trapped air mass, and engine operating conditions. To optimize the HES ratio under different conditions, it is crucial to understand how H2DF combustion differs from diesel combustion and how this limits engine operation and impacts emissions. To investigate these effects, a heavy-duty class 8 truck fitted with an H2DF system

Farzam, Reza, Guan, Mang, Gmoser, Raine, Steiche, Patrick, Kirchen, Patrick, McTaggart-Cowan, Gordon

Research on Turbocharger Surge Detection Based on Multi-Domain Composite Features of Acoustic Signals

2025-01-8253

04/01/2025

Taking a certain type of diesel engine turbocharger as the research object, a detailed study on the identification of turbocharger surge based on non-intrusive acoustic signals was conducted, and a novel turbocharger surge identification method based on multi-domain composite features of acoustic signals was proposed. The data related to the acoustic signals were collected through a series of supercharger surge reproduction experiments, and subsequently, a comprehensive database of these acoustic signals was established. Based on the multi-domain perspective of the time domain and frequency domain, 35 specific features were selected and extracted; the contribution of each individual feature to the occurrence of wheezing was calculated using the random forest algorithm, and the core contributing features were selected to be combined into a comprehensive multi-domain composite feature. This composite feature was then used for the recognition of turbocharger surge, serving as a highly

Zhu, Jiaxu, Zheng, Hongyu, Zong, Changfu

DME-to-Propane Mixture Effects on a Light Duty Compression Ignition Engine

2025-01-8415

04/01/2025

Fuels that can be produced in a sustainable manner are of high interest because they can provide an essential step toward net zero emissions vehicles. This study examines the combustion of two such fuels, Dimethyl Ether (DME) and propane, in a compression ignition, 4-cylinder, 2.2L engine running with mixtures of DME-to-Propane ranging of 100%-0%, 85%-15%, 75%-25%, and 65%-35% by weight. Testing was conducted at 2000rpm - 100Nm, an important representative point in the FTP certification cycle. For each fuel mixture, conditions tested include sweeps of boost, EGR and injection pressure. Tests are mainly conducted at a constant combustion timing with CA10 of -1 deg with respect to TDC, with an engine controller combustion feedback system based on in-cylinder sampling of pressure. Trends of NOx, HC, and CO are similar for the range of DME-to-propane, from 100%-0% to 75%-25%. Boost and injection pressures had the most notable impact on the heat release traces. Higher boost, from

De Ojeda, William, Wu, Simon (Haibao), Hall, Carrie, Ankobea-Ansah, King, Hassan, Hafiz Ahmad, Harrison, Christopher

Effect of Catalyst Coating Strategy on NOx Reduction and Passive Soot Oxidation for Selective Catalytic Oxidation-Selective Catalytic Reduction Catalyst on Diesel Particulate Filter

2025-01-8490

04/01/2025

Selective catalytic oxidation/reduction catalysts coated on diesel particulate filters (SDPF) are an important technology route to meet next-stage emission regulations. The previous research of the research group showed that compared with SDPF coated with Cu-SSZ-13, the SDPF coated with novel selective catalytic oxidation-selective catalytic reduction (SCO-SCR) catalyst, which combined MnO2-CeO2/Al2O3 and Cu-SSZ-13, can simultaneously improve NOx reduction and soot oxidation performance. Catalyst coating strategy is an important parameter affecting the performance of SDPF. In this study, the effects of different coating strategies of SCO-SCR catalysts (C25, C50, C75, and C100) on the performance of NOx reduction and soot oxidation in SDPF were investigated. The results show that, as the inlet gas temperature increases, NO emissions first decrease and then increase, NOx conversion efficiency first increases and then decreases, and the rich-NO2 area, NH3 oxidation rate, N2O, CO, CO2

Chen, Ying-jie, Tan, Piqiang, Yao, Chaojie, Lou, Diming, Hu, Zhiyuan, Yang, Wenming

Impact of Oxidation Catalyst Formulation and Space Velocity on Performance with Conventional and Renewable Fuels

2025-01-8495

04/01/2025

Prior study with biodiesel and its blends with ultra-low sulfur diesel (ULSD) and renewable diesel (RD) showed that a commercial diesel oxidation catalyst (DOC) is unable to effectively oxidize neat biodiesel (B100) or high-level biodiesel blends injected into the exhaust of a diesel engine at challenging conditions of low temperature, high exhaust flow rate and high dosing rate. In steady-state performance tests, the performance of blends up to B50 in ULSD or RD was nearly equivalent to ULSD at the lowest exhaust flow rate or for exhaust temperature over 340°C for medium and high flows. ULSD blends above 50 vol% biodiesel exhibited reduced thermal efficiency and DOC outlet temperature with increasing dosing rate and required exhaust temperatures over 400°C to achieve similar performance as ULSD. For RD blends at higher flow rates and temperatures below 300°C even B10 blends showed some loss in performance at the highest dosing rates. Data showed an increase in lightoff temperature

Lakkireddy, Venkata, Weber, Phillip, McCormick, Robert, Howell, Steve

10 % Fuel Economy Benefit at Part Load and up to 33 % at Idle for a Diesel Engine via Reducing Friction. Testing the Rotating Liner Engine and an Identical Baseline Under Load

2025-01-8390

04/01/2025

The Rotating Liner Engine (RLE) is a design concept where the cylinder liner of a heavy-duty Diesel engine rotates at about 2-4 m/s surface speed to eliminate the piston ring and skirt boundary friction near the top and bottom dead center. Two single cylinder engines are prepared using the Cummins 4BT 3.9 platform, one is RLE, the other is baseline (BSL), i.e. conventional. In 2022, we published the test results of the RLE under load, but we lacked detail test data for the baseline. In this new set of experiments, we compare the RLE performance at idle and under load of up to about 7 bar IMEP (indicated mean effective pressure) to the baseline under similar conditions. It has been proven that the elimination of metallic contact between the compression rings and cylinder wall takes place with a liner speed of 1.5-2.3 m/s surface speed (283-426 rpm for the 102 mm bore) for the 850-1280 rpm crankshaft speed. The RLE FMEP is substantially reduced under load, which is a trend opposite to

Dardalis, Dimitrios, Hall, Matthew, Riley, Sebastian, Basu, Amiyo, Matthews, Ron

Design of a High-Pressure Fuel System for Use with Dimethyl Ether

2025-01-8441

04/01/2025

The paper documents the modeling and experimental work on a common rail fuel injection system for Dimethyl Ether, a potential diesel substitute with a low carbon intensity signature. The DME fuel system is deployed on a light duty 2.2L compression ignition engine. The paper describes the injector optimization to shift to higher flows to account for the lower heating value and density of the DME when compared to diesel. The type of the injection system used for the DME application is an advanced rendering of the Common rail noted for a one-piece piston-needle injector construction and a solenoid driven spill valve featuring a pressure balanced poppet. A dedicated high-pressure fuel pump designed to pressurize DME is used. The design results in a fast acting open and close injection event, reduced leakage, with reduced cavitation in the fuel injector volume. Design parameters for system optimization included fill and spill orifices, needle lift, bias spring, and injector hole size. The

De Ojeda, William, Wu, Simon (Haibao)

Evaluating the Potential of a Turbo-Compound System for a Heavy-Duty Natural Gas Engine: A Modelling Study

2025-01-8355

04/01/2025

Combining a low-carbon content fuel, such as natural gas, with a high-efficiency engine can reduce greenhouse gas emissions significantly in hard-to-electrify long-haul trucking applications. Turbo-compounding, where an additional power turbine is installed in the exhaust stream after the turbocharger turbine, can extract useful amounts of energy from diesel engine exhaust at high loads. This work assesses the net benefits of combining turbo-compounding with a high-efficiency, natural gas fuelled heavy-duty engine. The effects on brake specific fuel consumption (BSFC), greenhouse gas emissions, and engine-out emissions of nitrogen oxides (NOx) and methane (CH4) are considered. The experimentally validated 1D model for a 13L diesel pilot- direct injection of natural gas, heavy-duty engine in GT-SUITETM is used to develop a series turbo-compound model. The effects of turbine sizes and flow capacities in fixed-geometry turbocharging and power turbines are evaluated on the engine’s

Balazadeh, Navid, Munshi, Sandeep, Shahbakhti, Mahdi, McTaggart-Cowan, Gordon

Assessment of a Heavy-Duty Diesel Engine Retrofitted to Dual-Fuel and Neat Methanol SI Operation

2025-01-8440

04/01/2025

This paper explores the potential of leveraging methanol's knock-resistant properties to facilitate both dual fuel (DF) and spark ignition (SI) operation in retrofitted heavy-duty (HD), high-speed marine engines. The study involves retrofitting an original 6-cylinder 7.15L CI diesel engine with port fuel injection (PFI) of methanol to enable DF operation. Later, the diesel injectors were replaced with six spark plugs allowing SI operation. Notably, efforts were made to minimize adaptations to the existing diesel engine, maintaining the compression ratio (CR) at 17.6:1 and retaining the same turbocharging pressure. This research aims to assess the feasibility of retrofitting conventional HD diesel engines (high CR, large bore) for dual-fuel and SI operation on methanol, with a focus on optimizing engine performance, while preserving key characteristics for HD applications, e.g. high torque and high power density. The high CR required spark retarding to prevent knock at higher loads in

Dejaegere, Quinten, Ballerini, Alberto, Demiddeleer, Sheldon, Vanderbeken, Thomas, Bracke, Kwinten, Gyselinck, Ben, D'Errico, Gianluca, Verhelst, Sebastian

Calculation of Airflow through the Air Cycle Technology’s Turboexpander and Its Effects on a Diesel Engine—Part I

2025-01-5023

03/31/2025

Amidst escalating climate change, the sustainability of internal combustion engine (ICE) vehicles, particularly in heavy transport, remains a critical challenge. Despite emission reductions from 1990 to 2020, ICEs, particularly diesel engines in Europe, continue to pose environmental challenges, notably in nitrogen oxide (NOx) emissions. This study proposes a novel solution to address the problem of NOx emissions by incorporating Air Cycle Technology’s (ACT) turboexpander into diesel engines. Acting as a second-stage compressor, intercooler, and expander, the turboexpander aims to lower intake air temperature, thereby mitigating NOx formation. The study utilizes a 4.4-l JCB-TCA-74 turbocharged diesel engine retrofitted with the ACT turboexpander as the experimental platform. The methodology involves using empirical formulae to calculate the key parameters of engine airflow for a standard turbocharged diesel engine followed by repeating the calculations for the same engine fitted with a

Fayaz, Farheen, Brace, Jordan, Allport, John, Javanbakht, Gina

Experimental Analysis of Soot and NOx Mitigation during Energy-Buffered Diesel Engine Transients

03-18-02-0014

03/24/2025

Transient operation of a diesel-fueled compression ignition engine will produce significant levels of engine-out criteria pollutants such as NOx and soot emissions due to turbocharger lag. Conventional pollutant mitigation strategies during tip-ins (large increases in load) are constrained by the soot–NOx trade-off—strategies that mitigate soot/NOx emissions often result in an increase in NOx/soot emissions. Hybridization offers the ability to use an e-machine as an energy buffer during a tip-in, allowing the engine to tip-in slower to give the turbocharger time to spin up and provide the necessary amount of air for clean, high-load operation. In this work, an in-line six-cylinder 12.8 L Detroit Diesel DD13 engine was used to study the impact of slowing the torque ramp rate of a tip-in on the effectiveness of transient emission reduction strategies for turbocharged diesel engines, including exhaust gas recirculation (EGR) valve closing, start of injection retard, and the air–fuel ratio

Gainey, Brian, Datar, Aditya, Bhatt, Ankur, Lawler, Benjamin

TOC

99-07-01-0TOC

02/17/2025

TOC

Tobolski, Sue

Mitigating Carbon Dioxide Emissions in Diesel Engines through the Application of Physical Adsorbents

2025-01-5008

02/13/2025

Graphical Abstract Abstract The world is targeting zero-emission standards by promoting flexi-fuel-based vehicles. In the automotive industry, IC engine-powered vehicle has a good market. Either IC or flexi-fuel engines are considered the safest mode of transport, one tedious problem needs to be addressed is their toxic exhaust emissions from those engines. However, there are many aftertreatment systems available to control HC, CO2, NOx, and PM emissions. To control CO2 emissions there is no aftertreatment system available. Physical adsorbents such as activated carbon and zeolite are going to be used in this work to reduce emissions from exhaust gases. Zeolite has a greater affinity toward NOx emission, and activated carbon has greater potential to capture HC and carbon dioxide emissions. Initially computational studies were carried out to evaluate back pressure developed in adsorbent chamber. Analysis was carried out by varying conical length of the adsorbent chamber (68 mm, 75 mm

Subramanian, MohanKumar, Muthiya, Solomon Jenoris, Pachamuthu, Senthilkumar, Naveena, B. E., Divya, G. S., Praveen Kumar, M. V.

Study on the Impact of Arrangement of Urea Injector and Mixer in Diesel Engine Selective Catalytic Reduction System on Ammonia Uniformity

02-18-02-0007

02/12/2025

With the continuous upgrading of emission regulations for internal combustion engines, the nitrogen oxide treatment capacity of selective catalytic reduction (SCR) aftertreatment needs to be continuously improved. In this study, based on a prototype of SCR aftertreatment, the impact of the arrangement of key components in the SCR system (urea injector, mixer, and catalyst unit) on ammonia uniformity was investigated. First, parameterized designs of the urea injector, mixer, and SCR unit were conducted. Then, using computational fluid dynamics (CFD), numerical simulations of the established aftertreatment system models with different parameter factors were performed under a high-exhaust temperature and a low-exhaust temperature conditions to study the impact of each individual parameter on ammonia uniformity. Finally, an optimized solution was designed based on the observed patterns, and the optimized samples were tested on an engine performance and emission test bench to compare their

Jie, Wang, Jin, Jianjiao, Wu, Yifan

Diesel Engine Performance and Combustion Imaging Analysis of Gas-to-Liquid and Polyoxymethylene Dimethyl Ether Blended Fuels

04-18-02-0010

02/12/2025

To reduce carbon dioxide emissions from automobiles, the introduction of electric vehicles to the market is important; however, it is challenging to replace all existing IC engine vehicles with electric ones. Consequently, there is increasing anticipation for the use of carbon-neutral fuels, such as e-fuels. This study investigates the effects of GTL (gas-to-liquid), as a substitute for e-fuel, produced from natural gas via the Fischer–Tropsch synthesis method and polyoxymethylene dimethyl ether (OMEmix) produced from methanol, on engine performance. Additionally, combustion image analysis was conducted using a rapid compression and expansion machine (RCEM). GTL fuel combusts similarly to conventional diesel fuel but has slightly lower smoke emissions because it does not contain aromatic hydrocarbons. Further, its high cetane number results in better ignition properties. During the combustion, unburnt hydrocarbons and smoke are generated in the spray flame interference region near the

Shibata, Gen, Yuan, Haoyu, Yamamoto, Hiroya, Tanaka, Shusuke, Ogawa, Hideyuki

Auxiliary Power Unit Electrical Interface Requirements for Class Eight Trucks

J2891_202502 (Current)

02/08/2025

This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck 12 VDC battery and electrical architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.

Truck and Bus Electrical Systems Committee

Cutting-Edge Coating Materials for Dual Fuel Diesel Engines Using Acetylene Aspiration

2025-28-0134

02/07/2025

A diesel engine with a Yttria Stabilised Zirconium (YSZ) thermal barrier layer (TBL) on the piston crown was used in an experiment. The aim of the investigation was to evaluate the influence of the thermal barrier layer on the efficiency and pollution levels of a diesel engine. The selection of YSZ as the coating material was based on its desirable physical properties including a high coefficient of expansion when exposed to heat, low degree of thermal conductivity, and a high Poisson's number. These characteristics make it a suitable material for use in coatings applied to engine components. In addition to their current research, the scientists are also focusing on identifying sustainable substitutes for conventional petroleum fuels. This is because of the growing concern over environmental impacts and the limited availability of fossil fuel resources. The researchers are seeking new options that are both environmentally friendly and capable of meeting the world's energy demands. By

Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree

Experimental Investigation and Operating Characteristics of LHR Engine Using Pongamia Pinnata and Azadirachta Indica Biodiesel Blend with Industrial Waste Additive

2025-28-0039

02/07/2025

The huge energy demand and environmental anxiety have focused the interest on alternative fuels to the diesel engine. This suggested the worldwide search for renewable, less pollutant and agricultural-based alternative fuel. Also, attention is given to increasing the efficiency of a conventional diesel engine when running on alternative fuels. Non-edible oil derived from Pongamia pinnata and Azadirachta indica seed oil blends as an alternative fuel have been considered for this study. Using Copper oxide (5% w/w), the two oils were transesterified for 6 hours at a temperature of 75 °C and a methanol to oil ratio of 20:1. The biodiesel samples that were produced underwent FTIR and GC-MS analysis. The results indicated that the FAME conversion for the biodiesel derived from Azadirachta indica and Pongamia pinnata was 99.19% and 97.93%, respectively. Diesel engine combustion components, viz., the piston crown and liner, were coated with Aluminium titanate thermal barrier material. The

R, Suresh, R, Ashwin, Uppuluri, Kiranbabu, T, MohanRaj

An Integrated Material Science Approach to Evaluate the Viability of Ethoxy Ethane and Rubber Seed (Heavea Brasiliensis) Biodiesel as Sustainable Fuel for Compression Ignition Engines

2025-28-0130

02/07/2025

The primary issues in using pure vegetable oils for internal combustion engines are their high soot output and reduced thermal efficiency. Therefore in the present investigation, a Heavea Brasiliensis biodiesel (HBB) is used as a carbon source of fuel and ethoxy ethane as a combustion accelerator on a compression ignition (CI) engine. In this investigation, an only one cylinder, four-stroke, air-cooled DI diesel engine with a rated output of 4.4 kW at 1500 rpm was utilized. Whereas heavea brasiliensis biodiesel was delivered straightly into the cylinder at almost close to the end of compression stroke and ethoxy ethane was sprayed instantly in the intake manifold in the event of intake stroke. At various loads, the parameter of ethoxy ethane volume rate were optimised. To minimise exhaust emissions, an air plasma spray technology was employed to cover the engine combustion chamber with a thermal barrier coating. Because of its adaptability for high-temperature applications, YSZ (Yttria

Sagaya Raj, Gnana, Natarajan, Manikandan, Pasupuleti, Thejasree

Impact of Hydrogen Enrichment on Performance and Emissions Characteristics of a Compression Ignition Engine Operated in Dual Fuel Mode with Karanja Oil Methyl Ester-Tire Pyrolysis Oil Blend

2025-28-0109

02/07/2025

The growing demand for fossil fuels and the search for alternatives have the potential to reduce emissions and enhance energy security. Karanja oil and tire pyrolysis oil (TPO) are identified as promising substitutes. This study examines the performance and emission characteristics of a 5.2 kW, 1500 rpm, four-stroke single-cylinder compression ignition engine. The engine was tested using diesel, the optimal combination of Karanja oil biodiesel (KOME) and TPO (50:50% volume ratio), and this KOME-TPO blend with hydrogen supplied in dual fuel mode at flow rates of 10 lpm, 20 lpm, and 30 lpm, designated as H10, H20, and H30, respectively. The results indicated that BTE for H30 was the highest, reaching 32.21% compared to 30.52% for diesel at 5.2 kW BP. BSEC for H30 was the lowest at 11.18 MJ/kWh, compared to 11.80 MJ/kWh for diesel at the same BP. Emission analysis showed that smoke and HC emissions were significantly lower for hydrogen-enriched blends. At 5.2 kW BP, HC emissions for H30

Duraisamy, Boopathi, Stanley Martin, Jerome, Chelladorai, Prabhu, Rajendran, Silambarasan, Marutholi, Mubarak, Madheswaran, Dinesh Kumar

Prediction of Diesel Engine NO _x Transient Emissions Based on a Combined Model with Convolutional Neural Network–Efficient Channel Attention–Bidirectional Gated Recurrent Unit

03-18-02-0012

02/06/2025

Widely used as power equipment, diesel engines emit NO x , which significantly threatens the well-being of both the ecosystem and individuals. The SCR system, which is employed to reduce NO x emissions from diesel engines, relies on precise control of the NO x emission levels. Addressing the challenge that traditional NO x emission prediction methods struggle to accurately forecast the emissions under transient operating conditions, this article introduces a deep learning model that integrates CNN, ECA, and BIGRU. The model’s necessary experimental data were collected during the hot phase of the WHTC, and input parameters were screened through correlation analysis. The model employs a CNN for feature extraction, integrates an ECA module to refine key feature processing, and utilizes BIGRU to capture temporal dynamics and dependencies, yielding predictive outcomes. Additionally, the model employs the Adam optimizer and combines it with BWO to adjust hyperparameters, thereby elevating

Peng, Yunlong, Wang, Guiyong, Wang, Yuhua, Wang, Feiyang, Wang, Zhiyuan, He, Shuchao

Study on Injection Parameters of Ammonia/Diesel Dual Direct Injection Low-Speed Engine

2025-01-7114

01/31/2025

With the adoption of the IMO Greenhouse Gas Emission Reduction Strategy Revision, the international shipping industry is facing huge pressure to reduce greenhouse gas emissions, and the conversion of ship power from traditional fossil fuels to low-carbon and zero-carbon fuels is the fundamental solution, and ammonia fuel, as a zero-carbon fuel, is an important direction for the development of ship power in the future. Based on a marine low-speed diesel engine with a bore of 520 mm, computational fluid dynamics (CFD) numerical simulation was carried out to study the effects of different diesel energy fractions, ammonia injection pressure, ammonia injection timing and ammonia diesel injection interval on the combustion and emission characteristics of the engine under the dual-fuel combustion mode of high-pressure dual direct injection. The calculation results show that under the condition of the current engine, 5% of diesel energy can reduce carbon emissions by 92.8% under the premise of

Yang, Jincheng, Liu, Long, Gui, Yong

Prediction of Combustion Process Based on Physics-Informed Data-Driven Model

2025-01-7034

01/31/2025

Predicting the ignition and heat release patterns during diesel combustion processes is of great significance for improving engine efficiency, reducing emissions, and enabling future low-carbon and zero-carbon flexible fuel control. However, traditional Wiebe physical models face challenges in handling the highly nonlinear nature and variable operating conditions of diesel combustion, failing to achieve accurate real-time prediction. Pure data-driven models demand large amounts of data and lack physical interpretability, while physical models based on parameter learning have restricted fitting accuracy due to structural and parameter constraints. To address these issues, this paper proposes a novel Physics-Informed Data-Driven Model. It defines data loss as the deviation between neural network predictions and measured data, and physical loss as the deviation between neural network derivatives and the differential form of the physical model. By minimizing the combined loss, which is a

Zheng, Jiaao, Song, Kang, Xie, Hui, Zhou, Shengkai, Sang, Hailang, He, Guanzhang

Experimental Study on Combustion and Emission Characteristics of a Two-Stroke Engine applying PODE/Methanol Blends Direct Injection

2025-01-7112

01/31/2025

In order to realize the Paris Agreement, which aims to strengthen the global response to climate change, conventional internal combustion engines (ICE) need to contribute to reducing carbon emissions and improving thermal efficiency. More importantly, in the face of energy shortages, it is urgent to search for sustainable fuels. Poly-oxymethylene dimethyl ethers (PODE) and methanol are both regard as important low-carbon, alternative fuels due to their high oxygen content. Using PODE can overcome the characteristics of methanol as a low-reactivity fuel with a low cetane number and poor ignition properties. In this study, the combustion and emission characteristics of PODE/methanol blends were investigated in a two-stroke direct injection engine. Firstly, the performance of the engine under pure PODE (P100) and PODE/methanol blends (P50) was compared. The results show that at BMEP of 0.31 MPa and injection timing of -8°CA ATDE, P50 blends have lower CO2, CO, NOX and THC emissions than

Dong, Pengbo, Sun, Zhuohan, Wang, Qingyang, Wang, Yang, Cui, Jingchen, Zhang, Zhenxian, Long, Wuqiang

Numerical Study on Combustion and Emission Characteristics of a Liquid Ammonia Direct Injection Ammonia-Diesel Engine

2025-01-7118

01/31/2025

Under the guidance of carbon neutrality goals, ammonia is expected to become a promising alternative fuel for internal combustion engines. Ammonia-diesel dual-fuel combustion not only effectively reduces carbon emissions but also addresses the issue of ammonia's slow combustion speed, ensuring good engine performance. Ammonia-diesel engines with liquid ammonia direct injection have the potential to further increase the ammonia energy ratio (AER) and reduce unburned ammonia, greenhouse gas (GHG) emissions, as well as NOx emissions. Based on a numerical model of a liquid ammonia direct injection ammonia-diesel engine, this paper compares two different injection system configurations: coaxial and non-coaxial liquid ammonia direct injection, and investigates the effect of AER on combustion and emission characteristics in the non-coaxial mode. The results show that, compared to the non-coaxial mode, the coaxial mode achieves more even fuel distribution and combustion distribution, higher

Liu, Yi, Chen, Qingchu, Qi, Yunliang, Wang, Zhi

Research of Pressure Control Based on Dither

2025-01-7040

01/31/2025

The purpose of the paper is to study the impact of dither on how to improve the pressure control capability in common rail system. The dither is directly operating to the inlet metering valve and making the metering flow accuracy. The correlation between rail pressure and metering flow was analyzed. Optimizing the inlet metering valve control is to improve the pressure control. To overcome the hysteresis problem of the inlet metering valve and improve its stability and rapidity on the pressure control. The PID control strategy based on the pressure control were applied in the common rail system and many papers have introduced the logical. But the dither application was seldom introduced in the common rail system. The dither was specified for the inlet metering valve. With the proper dither signal, the stick-slip motion of the metering valve spool converted to a steady one and the dynamic performance was optimized. To verify the theoretical and calibrated the proper dither signal, the

Kuang, Pengda, Chen, Huiqing, Zhang, Jing, Ran, Ye

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