Browse Topic: On-board energy sources

Items (27,263)
Different approaches are undertaken to mitigate the impact of the transport sector on climate change. Alongside electrifying powertrains, sustainable e-fuels such as polyoxymethylene dimethyl ethers (OME) are considered a promising bridging technology for different applications. However, this requires that the engines are optimized for the new fuels. Accordingly, this study aims to optimize the numerical spray modeling of OME in CONVERGE. Based on the KH–RT break-up model, the spray simulations of three different commercial injectors for heavy-duty applications are analyzed regarding the predictability of the liquid and gaseous penetration lengths and the total simulation time. A sensitivity analysis is conducted for the turbulence model, mesh size, and spray parameters prior to optimizing the spray model and validating it with experimental results. While each parameter individually influences the different phases of the injection event, the sensitivity analysis reveals that the break
Zepf, AndreasHärtl, MartinJaensch, Malte
Increasing global pressure to reduce anthropogenic carbon emissions has inspired a transition from conventional petroleum-fueled internal combustion engines to alternative powertrains, including battery electric vehicles (EVs) and hybrids. Hybrids offer a promising solution for emissions reduction by addressing the limitations of pure EVs such as slow recharge and range anxiety. In a previous research endeavor, a prototype high-power density generator was meticulously designed, fabricated, and subjected to testing. This generator incorporated a compact permanent magnet brushless dynamo and a diminutive single-cylinder two-stroke engine with low-technology constructions. This prototype generated 8.5 kW of electrical power while maintaining a lightweight profile at 21 kg. This study investigates the performance and emissions reduction potential by adapting the prototype to operate on methanol fuel. Performance and emissions were experimentally evaluated under varying operating conditions
Gore, MattNonavinakere Vinod, KaushikFang, Tiegang
With the growing energy crisis, people urgently need green energy sources to replace fossil ones. As a zero-emission clean energy source, the proton-exchange membrane fuel cell (PEMFC) has received growing attention from researchers due to its broad practical application. However, the large-scale application of PEMFC is currently impeded by their unsatisfying power output and high cost. PEMFC is composed of multiple components, among which the catalyst layer significantly affects the output power and cost of PEMFC. Drastically reducing the amount of platinum in the catalyst layer can bring great benefits to PEMFC, yet causing the large voltage loss associated with enlarged local oxygen molecule transport. Cutting down the platinum content in the catalyst layer can yield substantial cost savings for PEMFC. Developing an efficient catalyst possessing enhanced oxygen reduction reaction (ORR) catalytic performance is conducive to the commercialization of low-Pt proton exchange membrane
Liu, YuchenLiu, XinCai, XinDu, AiminLin, Rui
Depletion of petroleum crude oil and its environmental impacts challenge future generations. Vegetable oils provide a sustainable alternative with benefits like anti-wear properties, biodegradability, and renewability. Kusum oil's ability to lower carbon emissions significantly and promote sustainable industrial practices highlights its potential as a viable green alternative. This research paper presents a comprehensive and comparative analysis of a sustainable, environmentally friendly bio-lubricant and nonedible vegetable oil like Kusum oil. Bio-lubricant is produced by transesterification followed by epoxidation, which is known as epoxidized kusum oil lubricant or dehydrated kusum oil (DKO). The process of epoxidation significantly enhances the properties of Kusum oil, making it a promising alternative to conventional lubricants. It is compared with a widely used conventional mineral oil lubricant like SAE10W40. DKO exhibits comparable density, viscosity index, pour point, and
Prabhakaran, JPali, Harveer SinghSingh, Nishant K.
The accurate extraction of internal operating parameters associated with multi-physicochemical processes forms the basis for precise modelling of solid oxide fuel cells (SOFCs), which serves as the foundation for predicting performance degradation and estimating the lifespan of SOFCs. In this work, a novel integration of the teaching-learning based optimization (TLBO) and collective intelligence (CI), referred as the teaching-learning based collective intelligence algorithm (TLBCI), is introduced. This algorithm utilizes diverse characteristic patterns, including current-voltage (I-V) curves and sequential output data, to enhance the overall identification of degradation process. Experimental data was gathered from a 3-cell SOFC short stack during a 640-hour durability test. The proposed parameter identification algorithm employs a collective intelligence framework, wherein sub-optimizers are based on genetic algorithm (GA) and individually tasked with processing specific formats of
Wang, ZheyuShen, YitaoSun, AoTongHan, BeibeiMa, XiaoShuai, Shijin
Due to advantages such as high efficiency, low emissions, and fuel flexibility, solid oxide fuel cells (SOFCs) have garnered significant attention as promising power sources for automotive applications. Nickel/yttria-stabilized zirconia (Ni/YSZ) is one of the most widely used anode materials in SOFCs, as it can catalyze both chemical and electrochemical reactions of carbon-containing fuels. However, the direct use of carbon-containing fuels can lead to carbon deposition on the Ni/YSZ anode, negatively impacting the performance and reliability of automotive SOFC systems. The diffusion of carbon atoms within nickel plays a crucial role in the carbon deposition process and requires further investigation. The oxygen atoms that spillover from YSZ also participate in main reactions such as carbon deposition and electrochemical reactions in Ni. Molecular dynamics (MD) is one of the main methods for studying atomic diffusion in crystalline structures. In this study, reactive force field
Du, HaoyuZhang, KaiqiXiao, MaZhang, XiaoqingShuai, Shijin
Aviation gas turbine engines typically utilize twin-orifice swirl atomizers to achieve a fine spray, widen the spray cone angle, and shorten spray penetration. However, using twin-orifice atomizers complicates the spray structure, and knowledge of the spray, especially in the near-field nozzle zone, remains limited. This study experimentally investigates the morphologies and structure of liquid fragments in the near-field nozzle of a twin-orifice atomizer. A high-speed backlit experimental system was developed to examine the liquid fragment morphologies and structures. The fragments are classified into spherical droplets, ligaments, and other irregular structural fragments. Results show that with increasing the pressure in the near field of the nozzle, the proportion of nearly round fragments decreases with increasing pressure. In contrast, the proportion of ligament-like fragments tends to increase. Besides, the particle size distribution did not change significantly within the 10 to
Pham Vu, NamManh, VuPham, Phuong XuanNguyen, Kien Trung
Simulated distillation (SimDis) uses wide bore capillary gas chromatography (GC) to provide a detailed volatility profile of blended gasoline. The boiling point distribution from SimDis analysis is correlated to the hydrocarbon contents of spark ignition fuels and provide the resolution necessary to characterize the compositions of the fuel. Recent publications on simulated distillation applied to spark ignition fuel reveal the merits of indexing a gasoline fuel so that it can be correlated to the tendency of particulate emissions from vehicles. With this in mind, SimDis can be a useful and quick tool in assessing the PM-formation potential of market gasolines. Heavy aromatic compounds are compounds identified as having at least 10 Carbons and 1 aromatic ring. These compounds that are present in spark ignition fuels are major contributors to vehicle particulate emissions. These compounds can be found in the higher boiling portion (T70+) of the distillation profiles. As demonstrated in
Goralski, SarahGeng, PatDozier, JonButler, Aron
Track testing methods are utilized in the automotive industry for emissions and fuel economy certification. These track tests are performed on smooth road surfaces which deteriorate over time due to wear and weather effects, hence warranting regular track repaves. The study focuses on the impact of repaving on track quality and surface degradation due to weather effects. 1D surface profiles and 2D surface images at different spatial frequencies were measured at different times over a span of two years using various devices to study the repave and degradation effects. Data from coastdown tests was also collected over a span of two years and is used to demonstrate the impact of track degradation and repaving on road load characterization parameters that are used for vehicle certification tests. Kernel density estimation and non-parametric spectral estimation methods are used to visualize the characteristic features of the track at different times. In the pre-processing stage, outliers
Singh, YuvrajJayakumar, AdithyaRizzoni, Giorgio
To study the real driving emission characteristics of light-duty vehicles fueled with liquefied petroleum gas (LPG) and gasoline in a high-altitude city, experimental investigations were performed on two LPG taxis and three gasoline passenger cars in Lhasa using a portable emission measurement system (PEMS). The results reveal that the emission factors of CO2, CO, NOx, and HC of LPG taxis are 159.19±11.81, 18.38±9.73, 1.53±0.46, and 1.27±0.99 g/km, and those of gasoline cars are 223.51±23.1, 1.51±0.68, 0.27±0.16, and 0.06±0.04 g/km, respectively. The emissions show strong relationships with driving mode, which is considerably affected by driving behavior. Furthermore, as vehicle speed increases, the emission factors of both LPG taxis and gasoline cars decrease. The emission rates of both types of vehicles are low and change slightly at a vehicle specific power (VSP) of 0 kW/t or below; After that, the rates slowly increase initially and then increase rapidly with increasing VSP. These
Lyu, MengXu, YanHuang, MeihongWang, Yunjing
The integration of low-octane gasoline with a compression ignition combustion system has been proposed as a strategy to reduce Well-to-Wheel CO2 emissions from automobiles using petroleum-based fuel. In the current situation where low-octane gasoline is not widely available in the market, onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. This requires “Cetane on Demand” technology, which enables compression ignition combustion with both commercial gasoline and low-octane gasoline. It is known that the ignition property of fuel is enhanced when the fuel is oxidized to generate hydroperoxides. Moreover, the use of N-hydroxyphthalimide (NHPI) as a catalyst promotes hydroperoxide generation at low temperatures. The objective of this study is to develop a device that enhances the ignition properties of gasoline through onboard fuel reforming. Initially, from the seven
Hashimoto, KohtaroYamada, YoshikazuMatsuura, KatsuyaKudo, TomohideChishima, HiroshiAl-Taher, MaryamKalamaras, ChristosAlbashrawi, Reem
Optimizing energy providers like fuel cells and engines involves considering various factors, constraints, and requirements. These include NVH (Noise, Vibration, and Harshness), durability, operating point efficiency, and customer expectations. Different energy providers prioritize these factors differently. For instance, NVH is crucial for engines due to customer expectations regarding start-up, sound, and power delivery based on accelerator input. In contrast, fuel cells face fewer constraints but must consider noise from electrical AC compressors and other devices, especially at lower vehicle speeds. However, operating point efficiency and durability are paramount for fuel cells, as they are expected to last as long as engines in conventional vehicles sold today. This paper proposes a holistic approach that begins at the vehicle or powertrain architecture level and designs an operating strategy that integrates all the aforementioned factors to enhance the operation of a fuel cell
Patel, NadirshKudupley, Harshal
This study evaluates the impacts of the gasoline compression ignition (GCI) engine on heavy duty long-haul trucks in both the Chinese and US markets. The study examines various aspects such as vehicle performance requirements, fuel consumption, emissions, and ownerships costs, and how they influence the implementation and impact of new technologies in these markets. By considering a wide variety of drive cycles, including standard regulatory cycles and real-world cycles, the study aims to identify the impact of varying degrees of powertrain electrification using diesel and GCI engines on fuel consumption and emissions. Additionally, this paper explores the viability of powertrain electrification in long-haul trucks by analyzing factors such as levelized cost of driving (LCOD), manufacturing costs, and energy costs. These considerations play a crucial role in determining the economic feasibility and attractiveness of electrification technologies in various driving scenarios and market
Nieto Prada, DanielaVijayagopal, RamYan, ZimingSari, RafaelHe, Xin
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, ScottLi, HuTomlin, Alison S.
In recent years, the stronger push for reducing GHG and NOx emissions has challenged vehicle manufacturers globally. In USA, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light Duty and Medium-Duty Vehicles released by EPA in April 2023 aims to reduce the CO2 emissions by 56% and 44%, respectively, for light and medium duty vehicles by 2032 from 2026 levels. It also includes the NMOG+ NOx standards, which require a 60 – 76% reduction by 2032 from 2026 levels for light to medium-duty vehicles. Europe also aims to reduce CO2 emissions by 55% by 2030 from 1990 levels and 100% by 2035. To achieve such low levels of CO2 emissions, especially in the near-term scenario of limited EV sales, hybridization of conventional powertrains has found renewed interest. While hybrid powertrains add complexity, if optimized well for the application, they can offer best tradeoff between upfront cost, range, payload, performance, emissions and off-ambient operation. This study
Fnu, DhanrajCorreia Garcia, BrunoPaul, SumitJoshi, SatyumFranke, Michael
The Tour engine is a novel split-cycle internal combustion engine (ICE) that divides the four-stroke Otto cycle of a conventional ICE between two separate cylinders, an intake and compression cylinder and a second expansion and exhaust cylinder, interconnected by an innovative charge transfer mechanism. The engine working fluid, air and fuel, is inducted into the engine and compressed by a dedicated compression cylinder, transferred with minimal pressure loss via an input port to a specifically designed combined spool shuttle transfer mechanism and combustion chamber. It is then ignited and then transferred from the combustion chamber via an exit port to a separate expansion cylinder where it is expanded and exhausted from the engine. The primary advantage of the Tour engine is that it provides the engineering freedom to independently design, control and optimize the compression, combustion, and expansion processes within a slider-crank piston engine. By decoupling the compression
Tour, OdedCho, KukwonHofman, YehoramAnderson, BradleyKemmet, RyanMorris, DanielWahl, MichaelBhanage, PratikSivan, EhudTour, GiladAtkinson, ChrisTour, Hugo
The upcoming EURO 7 and EPA Tier 4 regulations and the possible China 7 are expected to tighten the tailpipe particulate emissions limits significantly. High performance Gasoline Particulate Filters (GPFs) with high filtration efficiency and low pressure drop would be mandated for gasoline engines to meet these stringent regulations. Due to packaging constraints, GPFs are often coated with three-way catalyst (TWC) materials to achieve four-way functionality. Ash accumulation in GPFs also has a significant impact on the performance of GPFs. This paper utilizes 3D CFD to predict the transient filtration efficiency and pressure drop of a washcoated GPF with ash accumulation during the soot loading process. Simulation results show a decent match with experimental data. The 3D CFD model also provides detailed information on soot penetration in the GPF wall substrate and soot cake characteristics on the wall. These information can be crucial for GPF wall substrate design and washcoating
Yang, PengzeCheng, Zhen
Three-way catalysts (TWCs) containing significant amounts of precious metals are commonly employed to purify exhaust emissions (CO, NOx, and THC) from gasoline-powered vehicles. A critical factor contributing to TWC degradation is the sintering of these precious metals. Maintaining the appropriate particle size and distribution of the metals is essential for optimal catalyst performance. In this study, palladium (Pd) nanoparticles with a uniform size were synthesized using ethylene glycol as a reductant under ultrasonic conditions, yielding particles in the range of 3 nm to 5 nm. These Pd nanoparticles were subsequently used to prepare three-way catalysts on cordierite substrates supplied by Corning (China) Inc. Chemisorption analysis revealed that the Pd active component in the catalysts prepared via the ultrasonic method exhibited higher dispersion than the state-of-the-art commercial catalysts. The aged catalysts were obtained after 150 hours of aging following the General Motors
Hao, ShijieLv, YananWang, WeidongRao, ChaoWei, WeiMao, BingbinChen, TaoZhao, Huawang
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, HuangchangZhao, Zhiyu
Since the obvious difficulties in realizing a lightweight long-range full electric powertrain, Internal Combustion Engines (ICEs) are still the most suitable solution for heavy-duty mobility. In a fossil fuel free scenario, bioethanol is one of the most interesting alternative fuels. Its high-octane number, high latent heat of vaporization and high laminar flame speed guarantee high performance with reduced pollutant emissions compared to other Spark Ignition (SI) engine fuels. However, ethanol evaporation and corrosivity represent quite serious challenges. This work aims at investigating the actual performance of a heavy-duty turbocharged SI ICE fueled with ethanol at full load and different engine speeds. A 1-D numerical model that includes fuel evaporation sub-models was developed in order to evaluate the engine performance, ensuring ethanol evaporation in each operating condition. The 1-D numerical model was validated through an experimental campaign carried out with the above
Falbo, BiagioPerrone, DiegoCastiglione, Teresa
This study evaluates the performance of alternative powertrains for Class 8 heavy-duty trucks under various real-world driving conditions, cargo loads, and operating ranges. Energy consumption, greenhouse gas emissions, and the Levelized Cost of Driving (LCOD) were assessed for different powertrain technologies in 2024, 2035, and 2050, considering anticipated technological advancements. The analysis employed simulation models that accurately reflect vehicle dynamics, powertrain components, and energy storage systems, leveraging real-world driving data. An integrated simulation workflow was implemented using Argonne National Laboratory's POLARIS, SVTrip, Autonomie, and TechScape software. Additionally, a sensitivity analysis was performed to assess how fluctuations in energy and fuel costs impact the cost-effectiveness of various powertrain options. By 2035, battery electric trucks (BEVs) demonstrate strong cost competitiveness in the 0-250 mile and 250-500 mile ranges, especially when
Mansour, CharbelBou Gebrael, JulienKancharla, AmarendraFreyermuth, VincentIslam, Ehsan SabriVijayagopal, RamSahin, OlcayZuniga, NataliaNieto Prada, DanielaAlhajjar, MichelRousseau, AymericBorhan, HoseinaliEl Ganaoui-Mourlan, Ouafae
Hydrogen fuel cell is one of paths to achieve carbon neutrality transportation. In the last two decades, significant improvements have been made in compactness, efficiency and durability of fuel cell systems. For heavy duty truck applications, a life span similar to heavy duty diesel engines is required. As a critical component in the fuel cell system, air compressors play an important role to meet fuel cell systems’ high efficiency and durability requirements. In this paper, a holistic approach has been taken to develop a series of airfoil bearing centrifugal compressors for a wide range of applications from forklift, passenger vehicles to commercial vehicles, and achieve high efficiency and durability of one million start-stops. In the new platform development, cooling circuit was optimized so that the external cooling air circuit for the rotor and air bearings is no longer needed, which resulted in 4% efficiency improvement. Hollow rotor structure was adopted to achieve lightweight
Wang, QianzhenYuan, XixinTao, ZhangFeng, Jin ZengWang, JuanXiao, YongZhou, LeiXin, Jun
The need for clean mobility launched multiple research directions in the powertrain field. While initially the battery electric vehicle (BEV) seemed the universal solution, the succession of pandemic emergencies and the resulting energetic crisis have defined a new scenario based on the multi-energy approach. One of the most promising technologies is the use of hydrogen in a fuel cell to generate electricity. This type of electric vehicle guarantees a shorter refueling time and a longer driving range than the battery electric one, becoming an enabling solution for long-haul or high-energy applications. In this study a combined 3D-CFD and 0D system analysis of an automotive Proton Exchange Membrane Fuel Cell (PEMFC) and system was carried out to provide a multi-scale analysis. In the first part, starting from a conventional parallel channel flow field configuration, the use of an optimization tool coupled with 3D-CFD simulations allowed to identify the optimal configuration in terms of
Martoccia, LorenzoAntetomaso, ChristianMerola, SimonaMarra, CarmineBreda, SebastianoD'Adamo, Alessandro
An experimental study was conducted on a multi-cylinder engine equipped with both intake and exhaust continuously variable valve duration (CVVD). Due to CVVD and continuous variable valve timing (CVVT), valve closing and opening timings of both intake and exhaust sides became decoupled, so that four valve timings (opening and closing timings of intake as well as exhaust sides) can be optimized under each engine condition. Theses independent valve timings allowed reductions of fuel consumption as well as particle number (PN) and stoichiometry combustion under full-load condition without compromise of performance. In addition, to reduce raw gaseous emissions and shorten light-off time of catalyst under catalyst heating condition, various valve timings were tested in the engine test bench. As results, nitrogen oxides (NOx) – total hydrocarbon (THC) trade-off relation was relieved by optimal valve timings including negative valve overlap duration compared to the base engine. As the last
Jung, JinyoungHan, SangyeonPark, SangjaeKwon, Ki YoungSon, YousangKim, Back-SikKim, Youngnam
In hybrid electric vehicles (HEVs), optimizing energy management and reducing system losses are critical for enhancing overall efficiency and performance. This paper presents a novel control strategy for the boost converter in hybrid electric vehicles (HEVs), aimed at minimizing energy losses and optimizing performance by modulating to a higher boost converter voltage only when necessary. Traditional approaches to boost converter control often lead to unnecessary energy consumption by maintaining higher voltage levels even when not required. In contrast, the proposed strategy dynamically adjusts the converter's operation based on real-time vehicle demands, such as driver input, Engine Start-Stop (ESS) events, Active Electric Motor Damping (AEMD), entry and exit transitions for Engine Fuel Cut-Off (DFCO), Noise-Vibration-Harshness (NVH) events like lash-zone crossing and other specific operational conditions. The control strategy leverages predictive algorithms and real-time monitoring
Basutkar, AmeyaHuo, ShichaoSullivan, ClaireBerger, DanielTischendorf, Christoph
This study numerically analyzed the gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs). The GDL, composed of carbon fibers and binder, plays a critical role in facilitating electron, heat, gas, and water transport while cushioning under cell compression. Its microstructure significantly influences these properties, requiring precise design. Using simulations, this study explored GDL designs by varying fiber and binder parameters and calculated gas diffusivity under wet conditions. Unlike previous studies, a novel model treated carbon fibers as beam elements with elastic binder connections, closely replicating structural changes under compression. Key properties analyzed include permeability, electrical conductivity, and gas diffusion efficiency under wet conditions. The optimized designs enhanced these properties while balancing trade-offs between electrical conductivity and mass transport. These findings provide valuable guidelines for advancing PEMFC technology
Ota, YukiDobashi, ToshiyukiNomura, KumikoHattori, TakuyaMaekawa, Ryosuke
Efficient and sustainable transportation in urban environments depends on understanding driving behaviors, and their implications. This study explores into the distinction between aggressive and non-aggressive driving patterns, leveraging an on-road driving dataset provided by an automotive company. By contrasting this data with established Fuel Economy cycles from United States Environmental Protection Agency (EPA) and employing curve-fitting techniques, the research not only reveals driving patterns but also predicts potential behaviors in unfamiliar scenarios. Results show significantly different acceleration profile patterns between different driving behaviors which has serious impact in fuel economy and environmental wellness. The findings highlights the environmental impact of driving behaviors, paving the way for environmentally responsible policy recommendations and sustainable driving practices.
Padmanaban, GandhimathiFeng, FredDai, EdwardSaini, AnkitHu, GuopengZhao, Yanan
Drivers present diverse landscapes with their distinct personalities, preferences, and driving habits influenced by many factors. Though drivers' behavior is highly variable, they can exhibit clear patterns that make sorting them into one category or another possible. Discrete segmentation provides an effective way to categorize and address the differences in driving style. The segmentation approach offers many benefits, including simplification, measurement, proven methodology, customization, and safety. Numerous studies have investigated driving style classification using real-world vehicle data. These studies employed various methods to identify and categorize distinct driving patterns, including naturalist differences in driving and field operational tests. This paper presents a novel hybrid approach for segmenting driver behavior based on their driving patterns. We leverage vehicle acceleration data to create granular driver segments by combining event and trip-based methodologies
Chavan, Shakti PradeepChinnam, Ratna Babu
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 AswathSun, ZongxuanKim, KennethKweon, Chol-Bum
The deployment of PEM fuel cell systems is becoming an increasingly pivotal aspect of the electrification of the transport sector, particularly in the context of heavy-duty vehicles. One of the principal constraints to market penetration is durability of the fuel cell which hardly meets the expected targets set by the vehicle manufacturers and regulatory bodies. Over the years, researchers and companies have faced the challenge of developing reliable diagnostic and condition monitoring tools to prevent early degradation and efficiency losses of fuel cell stack. The diagnostic tools for fuel cell rely usually on model-based, data driven and hybrid approaches. Most of these are mainly developed for stationary and offline applications, with a lack of suitable methods for real-time and vehicle applications. The work presented is divided into two parts: the first part explores the main degradation conditions for a PEMFC and characteristics, advantages, and application limits of the main
Di Napoli, LucaMazzeo, Francesco
Fuel cell electric vehicles (FCEVs) are gaining increasing interest due to contributions to zero emissions and carbon neutrality. Thermal management of FCEVs is essential for fuel cell lifespan and vehicle driving performance, but there is a lack of specialized thermal balance test standards for FCEVs. Considering differences in heat generating mechanism between FCEVs and internal combustion engine vehicles (ICEVs), current thermal balance method for ICEVs should be amended to suit for FCHVs. This study discussed thermal balance performance of ICEV and FCHVs under various regulated test conditions based on thermal balance tests in wind tunnel of two FCEVs and an ICEV. FCEVs reported overheat risk during low-speed climbing test due to continuous large power output from fuel cell (FC). Frequent power source switches between FC and battery were observed under dual constrains of fuel cell temperature and battery state of charge (SOC). Significant temperature exceedance of ICEV occurred
Fang, YanhuaMin, YihangMing, ChenLi, HongtaoLi, DongshengHe, ChongMao, Zhifei
On-board diagnosis (OBD) of gasoline vehicle emissions is detected by measuring the fluctuations of the rear oxygen sensor due to the time-dependent deterioration of the oxygen storage capacity (OSC) contained in the automotive catalyst materials. To detect OBD in various driving modes of automobiles with an order of magnitude higher accuracy than before, it is essential to understand the OSC mechanism based on fundamental science. In this study, time-resolved dispersive X-ray absorption fine structure (DXAFS) using synchrotron radiation was used to carry out a detailed analysis not only of the OSC of ceria-based complex oxides, which had previously been roughly understood, but also of how differences in design parameters such as the type of precious metals, reducing gases (CO and H2), detection temperatures, and mileages (degree of deteriorations) affect the OSC rate in a fluctuating redox atmosphere. A fundamental characteristic was clearly demonstrated in ceria-based complex oxides
Tanaka, HirohisaMatsumura, DaijuUegaki, ShinyaHamada, ShotaAotani, TakuroKamezawa, SaekaNakamoto, MasamiAsai, ShingoMizuno, TomohisaTakamura, RikuGoto, Takashi
This work presents a computationally inexpensive but effective method for an initial assessment of component sizing and power-split for fuel cell hybrid electric heavy-duty trucks. As a first step, the proposed method employs a prototypical longitudinal vehicle model to generate power demand at every instant of a representative drive cycle. Subsequently, six fuel cell and battery sizing combinations, each providing a peak continuous system power of 400 kW, are identified based on drive cycle power demands, commercially available fuel cell sizes, and Department of Energy (DOE) sizing targets. Ultimately, for each sizing combination, a proportional-integral (PI) controller with anti-windup is implemented to split power between the fuel cell and battery. In this study, the controller is tuned to reduce hydrogen consumption while meeting the instantaneous power demand and maintaining the battery state-of-charge (SOC) between 0.3 and 0.7. The results indicate that increasing the fuel cell
Mandviwala, AliYesilyurt, SerhatStefanopoulou, Anna
In the modern automotive industry, improving fuel efficiency while reducing carbon emissions is a critical challenge. To address this challenge, accurately measuring a vehicle’s road load is essential. The current methodology, widely adopted by national guidelines, follows the coastdown test procedure. However, coastdown tests are highly sensitive to environmental conditions, which can lead to inconsistencies across test runs. Previous studies have mainly focused on the impact of independent variables on coastdown results, with less emphasis on a data-driven approach due to the difficulty of obtaining large volumes of test data in a short period, both in terms of time and cost. This paper presents a road load energy prediction model for vehicles using the XGBoost machine learning technique, demonstrating its ability to predict road load coefficients. The model features 27 factors, including rolling, aerodynamic, inertial resistance, and various atmospheric conditions, gathered from a
Song, HyunseungLee, Dong HyukChung, Hyun
In addition to electric vehicles (EVs), hydrogen fuel cell systems are gaining attention as energy-efficient propulsion options. However, designing fuel cell vehicles presents unique challenges, particularly in terms of storage systems for heavy hydrogen tanks. These challenges impact factors such as NVH (noise, vibration, and harshness) and safety performance. This study presents a topology optimization study for Hydrogen Energy Storage System (HESS) tank structure in Class 5 trucks, with a focus on enhancing the modal frequencies. The study considers a specific truck configuration with a HESS structure located behind the crew cab, consisting of two horizontally stacked hydrogen tanks and two tanks attached on both sides of the frame. The optimization process aimed to meet the modal targets of this hydrogen tank structure in the fore-aft (X) and lateral (Y) directions, while considering other load cases such as a simplified representation of GST (global static torsion), simplified
Yoo, Dong YeonChavare, SudeepViswanathan, SankarMouyianis, Adam
Camera-based mirror systems (CBMS) are being adopted by commercial fleets based on the potential improvements to operational efficiency through improved aerodynamics, resulting in better fuel economy, improved maneuverability, and the potential improvement for overall safety. Until CBMS are widely adopted it will be expected that drivers will be required to adapt to both conventional glass mirrors and CBMS which could have potential impact on the safety and performance of the driver when moving between vehicles with and without CBMS. To understand the potential impact to driver perception and safety, along with other human factors related to CBMS, laboratory testing was performed to understand the impact of CBMS and conventional glass mirrors. Drivers were subjected to various, nominal driving scenarios using a truck equipped with conventional glass mirrors, CBMS, and both glass mirrors and CBMS, to observe the differences in metrics such as head and eye movement, reaction time, and
Siekmann, AdamPrikhodko, VitalySujan, Vivek
The performance of a second-generation Toyota Mirai fuel cell was characterized as part of the SwRI internal research program. This data was used to develop a supervisory controller scheme designed to balance the plant for the fuel cell system during steady-state and transient vehicle conditions. This was accomplished using a Supervisory Integrated Controller (SIC) implemented on a Real-time Power Electronics Control System (RPECS) with a Simulink-based control algorithm. The actuators of interest are the three hydrogen injectors at anode inlet, air compressor and three air side valves on at the cathode inlet. The FC power measurement and pressure sensor readings at the anode and cathode were utilized as real-time feedback for the controller operation. The aim of the controller was to achieve and maintain the power target set by the hybrid powertrain ECU present on the vehicle, which is responsible for balancing power on the fuel cell and battery over the high-voltage bus. These
Chundru, Venkata RajeshKubesh, MatthewLegala, Adithya
Diverse solutions will likely be needed to decarbonize the commercial truck sector in the United States. Battery-powered vehicles play a predominant role but in some cases, fuel cell trucks are more advantageous for the consumer. This study examines several medium- and heavy-duty applications designed for different driving range requirements to identify the design space where battery and fuel cell trucks are attractive. Also considered are the impacts of purchase price, fuel cost, and vehicle usage. We examine the top 10 truck classes as well as bus applications based on vehicle population, fuel usage, and driving distances. We assume a 2030 scenario where both batteries and FC systems become less costly and more efficient, as targeted by the U.S. Department of Energy. Even for smaller-class vehicles, where battery electric vehicles are expected to be the most economical among clean vehicle solutions, the results are not straightforward. Based on vehicle design, usage, and external
Vijayagopal, RamBirky, Alicia
The low emission of carbon and minimum level of soot formation in combustion engines and turbines strategy is adopted by many countries to counteract global warming and climate change. The use of ammonia with hydrocarbon fuels can limit the formation of soot and carbon emissions due to non-carbon atoms. The current study explores the use of ammonia with air at coflow flame conditions, which was not tested before. It may give the choice for diesel cycle engines to use the ammonia either with air or fuel. The combustion and emission characteristics of methane coflow flame were studied at low pressure and air polluted by ammonia conditions. The results showed that a significant decline in carbon formation was observed when ammonia was boosted, 5-10%. The impact of sub-atmospheric pressure, 90-70 KPa, on COx development was higher than that of NH3 addition, 0-5%, thanks to the lower formation of hydroxymethylium, formaldehyde, and aldehyde radical. In the environment of lower pressure, the
Hina, AnamAkram, M ZuhaibShafa, AmnaAkram, M Waqar
Series hybrid vehicles with internal combustion range extenders are a promising solution for sustainable transportation. In this application, net zero carbon emissions can be achieved using renewable fuels. Fischer-Tropsch-derived e-gasolines/naptha allow for high energy density and safe liquid fuels. However, Fischer-Tropsch naptha fuel derivatives must undergo several processing stages to reach current engine-grade octane ratings, negatively affecting the synthesis's profitability and energy efficiency. Gasoline engine technologies capable of operating with low-octane fuels could allow the adoption of unprocessed Fischer-Tropsch gasoline. The rotary Wankel engine design suits range extenders thanks to its high power-to-size ratio. In this study, the knocking tendency of homogenous charge spark-ignition rotary Wankel engines is numerically assessed through Chemkin-Pro spark-ignition engine zonal model for knock assessment. Rotary Wankel engines are modeled by providing the
Brunialti, SirioVorraro, GiovanniTurner, JamesSarathy, Mani
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 KaundinyaLien, Hao-PinTorelli, RobertoMotily, AustenLee, TonghunKim, KennethMayhew, EricKweon, Chol-Bum
Reducing emissions in individual transport requires electrification and hybridization. Emission reduction depends on the degree of electrification, the specific powertrain design and optimized components. This is especially true for hybrids with the highest number of components, consisting of combustion engine, transmission, electric motors and batteries. The integration of the electric motor in the transmission for dedicated hybrid transmissions leads to many possible concepts. Computer-aided powertrain synthesis is therefore needed to develop new powertrain architectures. In a publicly funded project, we have developed a powertrain synthesis that includes a combustion engine synthesis and a transmission synthesis. In this paper we focus on the impact of the engine concept on the powertrain dimensioning, fuel consumption, performance and operating behavior in a parallel hybrid configuration. In addition to different engine concepts, the electrical power is also varied to discuss the
Sturm, AxelHenze, RomanKüçükay, FeritWolgast, CarstenEilts, Peter
Many countries around the world are currently working toward carbon neutrality, which would reduce greenhouse gas emissions to net zero by 2050. To achieve carbon neutrality, the search for new fuels to replace gasoline has been active. This study focuses on hydrogen and methanol fuels and examines their effects on plain bearings when these fuels are used in internal combustion engines. Compared to gasoline, these fuels differ significantly in the composition of gases produced after combustion. It is assumed that nitric acid, etc. will be mixed in the engine oil when hydrogen is combusted whilst formic acid, etc. will be mixed in the engine oil when methanol fuel is combusted. For this reason, corrosion tests were conducted by adding nitric acid or formic acid solution to the engine oil then placing plain bearings in the deteriorated oil. The results confirmed that significant corrosion of the bismuth overlay coating occurred and subsequently the performance of plain bearings may
Kondo, MakotoKawaura, HirokiShiroya, TomoyasuWatanabe, Airi
Dimethyl ether (DME) is widely regarded as a suitable energy source for compression ignition power systems because of its high reactivity. It has been widely reported that DME possesses a significantly low propensity to form soot, hindering the innate NOx-soot trade-off encountered with diesel fuel operation. Beyond the fuel-borne oxygen content of DME, its unique physical properties present a contrasting combustion behavior which may be advantageous to direct injection systems, especially concerning the mixing-controlled combustion mode. This work aims to detail the energy conversion efficacy of DME through heat release characterization and exhaust emission speciation. The tests were controlled within a single-cylinder research engine with an off-board high-pressure injection system to handle liquified DME up to 1000bar. To mitigate interference in fuel additives over the combustion behavior, the high-pressure fuel system specifically managed neat DME. The in-cylinder pressure was the
Leblanc, SimonCong, BinghaoLeach, JaceYu, XiaoReader, GrahamZheng, Ming
Renewable and alternative liquid fuels are being evaluated for their equivalence with ultra-low sulfur diesel (ULSD) in terms of engine and emission control system performance. Our previous research showed an elevated lightoff temperature for diesel oxidation catalyst (DOC) and lower DOC thermal efficiency for biodiesel blends into ULSD with more than 20% biodiesel. Here we report a similar DOC performance study to gage the performance of blends of biodiesel and hydrocarbon renewable diesel (RD) also made from fats and oils feedstocks. The same DOC used previously was used to evaluate RD blends with biodiesel up to 60 vol% (B60R40) in decrements of 10%. The performance of the DOC was evaluated on a steady-state performance cycle and a transient lightoff curve. Similar to previous results, the performance of the DOC is significantly affected by even low blend levels of biodiesel. At low flow rates 50% (B50R50) and higher biodiesel blends have a poor performance defined as the lightoff
Lakkireddy, VenkataWeber, PhillipMcCormick, RobertHowell, Steve
Otto cycle internal combustion engines have undergone technological developments that can be fueled by various types of fuels in different mixture proportions. To achieve this, a detailed study of the main factors that influence the engine combustion process is necessary. The objective of this study is to evaluate the effects of varying the ignition advance on the performance parameters and vibration level of the engine operated with regular gasoline, podium gasoline, ethanol and a mixture of ethanol with regular gasoline. The experimental tests consisted of operating an Otto cycle engine on a bench dynamometer under full load conditions, varying rotation and ignition advance by 5, 10 and 20% in relation to the original ignition advance and correlating the levels of pre-ignition, knock, engine vibration levels with engine performance parameters. The results showed that the engine vibration level was influenced by the type of fuel used, engine performance parameters and the presence of
Santana, Claudio
India, with its low per capita income vast population and growing middle class, represents a significant market for low-cost, fuel-efficient automobiles. As the largest two-wheeler market globally, a transition to four-wheelers is underway, further driving the demand for affordable vehicles. This necessitates the design and development of low-priced vehicles equipped with efficient and economical powertrains. Globally, stringent regulations like Corporate Average Fuel Economy (CAFE), Worldwide Harmonized Light Vehicles Test Cycles (WLTC), and Real Driving Emissions (RDE) are pushing manufacturers to develop fuel-efficient vehicles. India has also adopted similar regulations, including CAFE2 and Bharat Stage 6-Phase 2 (BS6-2), to improve fuel economy and reduce emissions. These regulations, coupled with the growing demand for affordable vehicles, have spurred innovation in engine technology. In response to these challenges, Maruti Suzuki India Limited (MSIL) has consistently focused on
Singh, AmandeepSingh, JaspreetJalan, AnkitKumar, Narinder
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