Browse Topic: Environment

Items (41,777)
Find
Optimization of Metallic Substrate by 1D simulations to fulfill High Power Cold Start Conditions2025-01-0308To be published on 07/02/2025
The future of the internal combustion engine is strictly related to his capability to have Life Cycle Emission comparable to the pure Battery Electric Vehicles. To achieve this goal, it will be necessary not only to have carbon free fuels but also to increase the hybridization of the powertrain in order to have lower fuel consumption. On the other hand, it will be necessary to reduce to almost zero any further emissions of pollutants. For this reason, highly sophisticated exhaust aftertreatment must be developed. One particular use case is the so-called High-Power Cold Start. This can occur for the Plug-In Hybrid Electric Vehicles when the transition from pure electric drive to ICE assisted drive happens during high load request, for example an acceleration on the freeway ramp. This use case has been evaluated by CARB and in many other works. Nevertheless, in this particular paper, the Authors would like to investigate which Metallic Substrate Technology fits better during a HPCS. This
Montenegro, Gianluca, Onorati, Angelo, Marinoni, Andrea, Della Torre, Augusto, Pace, Lorenzo, Konieczny, Katrin, Laurell, Mats, Klövmark, Henrik
Technical Paper
In Situ Observation of Different Soot Layers in a Model Filter Channel During Its Regeneration2025-01-0312To be published on 07/02/2025
To keep the air clean, wall-flow particulate filters are predominantly used in the exhaust gas after-treatment systems of combustion engines to remove reactive soot and inert ash particles. These filters consist of parallel porous channels with alternately closed ends, effectively separating particles by forming a layer on the filter surface. However, the particulate layer increases the pressure drop, requiring periodic regeneration. During regeneration, soot oxidation breaks up the particulate layer, while resuspension and transport of individual agglomerates may occur. These phenomena are influenced by gas temperature and velocity, as well as dispersity and the reactivity of the soot particles. Sustainable fuels can produce different types of soot with different reactivities and dispersities, therefore this study focuses on the influences of soot dispersity and reactivity by varying the reactive particle system. A model wall-flow filter channel is used for the investigation, enabling
Desens, Ole, Hagen, Fabian P., Meyer, Jörg, Dittler, Achim
Technical Paper
Prediction of hazardous gaseous emissions from a gasoline engine during cold starts using machine learning methods2025-01-0321To be published on 07/02/2025
Internal combustion engines generate higher exhaust emissions of hazardous gases during the initial minutes after engine start. Experimental data from a state-of-the-art turbo-charged 3-cylinder, 999 cc gasoline engine are used to predict cold start emissions using two Machine Learning (ML) models: a Multilayer Perceptron (MLP) which is a fully connected neural network and an Encoder-Decoder Recurrent Neural Network (ED-RNN). Engine parameters and various temperatures are used as input for the models and NOx (Nitrogen Oxides), CO (Carbon monoxide) and unburned hydrocarbon (UHC) emissions are predicted. The dataset includes time series recordings from the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) and four Real Diving Emissions (RDE) cycles at ambient and initial engine temperatures ranging from -20 °C to +23 °C. In total, 21 cases are considered, consisting of eight different ambient temperatures and five distinct driving cycles. Each case consists of a sequence of 2500
Mangipudi, Manoj, Denev, Jordan A., Bockhorn, Henning, Trimis, Dimosthenis, Koch, Thomas, Debus, Charlotte, Götz, Markus, Zirwes, Thorsten, Hagen, Fabian P., Tofighian, Hesam, Wagner, Uwe, Braun, Samuel, Lanzer, Theodor, Knapp, Sebastian M.
Technical Paper
Application of Sustainable Aviation Fuels in Compression-Ignition Aviation Engines: In-Flight Investigations2025-01-0317To be published on 07/02/2025
To achieve a significant reduction in net CO₂ emissions in the aviation sector, sustainable aviation fuels (SAFs) are considered a key factor. Current research efforts are therefore focused on SAFs, which exhibit properties that differ from conventional kerosene, particularly in aspects critical to compression-ignition (CI) engines, such as cetane number, evaporation behavior or lubricity. These differences necessitate dedicated investigations to assess their suitability and performance in such engines. However, real operating conditions — such as intake air- and exhaust- pressure levels during flight — cannot be fully replicated on standard engine test benches. For this reason, real flight experiments were conducted to address these limitations. Notably, this work marks the first instance of in-flight testing of SAFs in CI aviation engines, constituting a significant milestone in this research area. In the course of these investigations, ASTM D7566 Annex A2-compliant HEFA
Kleissner, Florian, Reitmayr, Christian, Hofmann, Peter
Technical Paper
Method for externally controlled availability of lubricating oil in internal combustion engines.2025-01-0302To be published on 07/02/2025
Reduced emissions in internal combustion engines (ICE) are a key component in reaching green-house-gas and pollutive emissions regulations. With increased effort, clean and efficient burning combustion cycles are being developed. With the need of even more efficient engines the friction of ICE engines plays an increasing role in engine efficiency. Also, ingress of lubricating oil into the combustion chamber is a source of particle emissions. Increased optimization to reduce parasitic drag in the piston assembly such as reduced ring pre-tension ore thinner grade oils further increase oil ingress into the combustion chamber with the result of increased particle emissions. The transport mechanisms of oil ingress into the combustion chamber therefore the topic of current research. Specially developed research engines with a vertical optical window have big potentials to visualize phenomena of the oil behavior inside the piston assembly in internal combustion engines. Therefore, these
Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Technical Paper
Optimized Cabin Heating Strategy for Battery Electric CEP Vehicles2025-01-0263To be published on 07/02/2025
Electromobility is gaining importance in the courier, express and parcel (CEP) sector, as parcel service providers increasingly rely on zero-emission vehicles to improve their CO₂ footprint. A common drawback of battery electric vehicles is their reduced range under cold operating conditions, due to the increased energy demand for cabin heating. Another CEP-specific factor influencing both energy consumption and cabin comfort is the frequent opening of doors during parcel delivery. Additionally, during delivery phases, the cabin cools down in the driver’s repeated absence from the cabin, as the heating is inactive. Nonetheless, a sufficient level of thermal comfort must be maintained during the driving phases between delivery stops. This paper presents an optimization-based strategy for the cabin heating of battery electric CEP vehicles. The objective is to maximize cabin comfort during driving phases while maintaining efficient energy consumption. For this purpose, a nonlinear model
Rehm, Dominik, Krost, Jonathan, Meywerk, Martin, Czarnetzki, Walter
Technical Paper
Life-Cycle Assessment of a Composite vs. a Metallic Bipolar Plate for Fuel Cell Applications: More Sustainable while Maintaining Same Performance Standards?2025-01-0298To be published on 07/02/2025
Faced with one of the greatest challenges of humanity – climate change – the European Union has set out a strategy to achieve climate neutrality by 2050 as part of the European Green Deal. Life Cycle Assessment (LCA), which among other aspects identifies climate change effects, is an important tool to assess the environmental characteristic of sustainable technologies or products to fulfill this ambitious target. In this context, research is presented that examines the ecological sustainability impacts of a metallic vs a composite bipolar plate made of innovative graphite-compound based foils for fuel cell applications. A bipolar plate is a central component of the fuel cell stack to ensure efficiency and durability. For this purpose, a LCA is performed for both bipolar plate materials. This assessment follows the methodology of DIN EN ISO 14040/44 and the EU Product Environmental Footprint framework. Focusing on cradle-to-gate system boundary conditions, the research emphasizes the
van Sloun, Andreas, Schroeder, Benedikt, Kexel, Jannik, Schmitz, Maximilian, Balazs, Andreas, Walters, Marius, Koßler, Silas, Pischinger, Stefan, Joemann, Michael
Technical Paper
Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion2025-01-0275To be published on 07/02/2025
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical
Herkenrath, Ferris, Lückerath, Moritz, Günther, Marco, Pischinger, Stefan
Technical Paper
Effect of Gasoline Component on Fuel Economy of WLTC Drive with EGR and Lean Combustion2025-01-0305To be published on 07/02/2025
It is becoming increasingly clear that research into alternative fuels, including drop-in fuels, is essential for the continued survival of the internal combustion engine. In this study, the authors have evaluated olefinic and oxygenated fuels as drop-in fuels using a single-cylinder engine and considering fuel characteristic parameters. The authors have assessed thermal efficiency by adding the EGR or air from 0 to the maximum value that allows stable combustion. Next, we attempted to predict fuel efficiency for four types of passenger cars (Japanese small K-car N/A, K-car T/C, Series-HV, and Power-split-HV) by changing the fuels. We created a model in OpenModelica to estimate fuel efficiency during WLTC driving. The results indicated that fuel economy could potentially be improved by adding an olefin fuel that burns stably even with a large amount of EGR or air and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was particularly
Moriyoshi, Yasuo, Xu, Fuguo, Wang, Zhiyuan, Tanaka, Kotaro, Kuboyama, Tatsuya
Technical Paper
Evaluation of Several Jet Fuels under Compression-ignition Operation on Thermal Efficiency, NOx, Particulate Matter, and Particle Size Distribution2025-01-0244To be published on 06/16/2025
Alternative fuels such as Fischer-Tropsch Synthesized Paraffinic Kerosene (FT-SPK) and Catalytic Hydrothermal Conversion Jet (CHCJ) are among those important sustainable aviation fuels (SAFs) for future transportation. However, these alternative fuels often vary in their fuel characteristics, which depend on feedstock and fuel production processes. Therefore, a detailed analysis of combustion, emissions, and efficiency of these alternative fuels must be performed under controlled experiments to understand the impact of fuel properties and operating conditions. Using a single-cylinder research engine (SCRE), extensive operating conditions were performed to realize any difference in performance that can be fundamentally understood by fuel properties (e.g., cetane number, heat of combustion, and density) of these fuels in comparison with Jet-A. The experimental setup includes high-speed data acquisition for combustion analysis and gaseous and solid emissions benches for nitrogen oxides
Cung, Khanh, Miganakallu Narasimhamurthy, Niranjan, Khalek, Imad, Hansen, Greg
Technical Paper
Comparison of HRD and Petro Diesel in Industrial Engine Applications2025-01-0243To be published on 06/16/2025
Renewable fuels are seen as a key enabler on the path to a lower carbon future. A low greenhouse gas fuel of particular interest is hydrotreated renewable diesel (HRD), also known as hydrotreated vegetable oil (HVO). HRD is of interest because it is a drop-in replacement to existing petroleum fuels used in diesel engines. An experimental investigation was undertaken to evaluate combustion characteristics of HRD versus a standard petroleum diesel. The work was carried out using a 2.5-liter fully instrumented single-cylinder research engine. This engine was chosen because it provides a very precise view of the difference in combustion and emissions of the fuels. Results represent the difference in combustion characteristics of the fuels, rather than potential differences in engine performance seen in a production engine, as each particular engine model will react a bit differently to the changes in combustion. The engine was operated according to three ISO 8178-4 test cycles: C1, D2, and
Bardell, Michael, Abi-Akar, Hind, Seiler, Patrick, Nash, Brady, McMahon, Donna, Ioannou, Marios
Technical Paper
Commercial Vehicle’s Exhaust Front Pipe Reliability Improvement through Virtual Simulation and Experimental Validation2025-01-0209To be published on 06/16/2025
The exhaust front pipe is a critical structural component in commercial vehicles, ensuring the leak-proof flow of exhaust gases into the exhaust after-treatment system while withstanding engine and frame vibrations. To isolate these vibrations, the front pipe is equipped with a flex connector capable of enduring various displacements at frequencies between 8-25 Hz. The position of the flex connector relative to the engine crank axis significantly impacts its structural reliability over its service life. This paper compares the existing design, which features a horizontally positioned flex connector, with a modified design that positions the flex connector vertically and changes the material from SS-304 to SS-321. Finite element analysis was conducted using Nastran software. The fatigue life of the existing flex connector design is approximately 1015 cycles. In contrast, the improved design demonstrates a fatigue life of 1727 cycles, representing a 70% increase in durability compared to
Chandel, Kushal, Paroche, Sonu, Namdev, Akhilesh, Jain, Shailendra, Patil, Keyur
Technical Paper
Comparison of spark and turbulent jet ignition in a fully ammonia-fueled engine2025-01-0201To be published on 06/16/2025
Ammonia (NH₃) is an emerging carbon-free fuel with the potential to decarbonize the energy sector. However, its widespread adoption is hindered by challenges like low flame speed, high ignition energy, and elevated emissions of nitrogen oxides (NOx) and unburnt NH₃. These limitations necessitate innovative combustion strategies for efficient and stable engine operation. This study investigates the potential of turbulent jet ignition (TJI) to overcome these challenges through the implementation of a pre-chamber, a small auxiliary chamber equipped with a spark plug to create hot, reactive jets that propagate into the main chamber, promoting rapid combustion from distributed ignition sites. In this work, TJI operation is compared to conventional spark ignition (SI) in a Cummins ISB6.7 engine retrofitted for 100% ammonia operation. Experiments were conducted at 1200 and 1800 RPM across varying loads (25%, 50%, 75%, and 100%) with equivalence ratio and spark timing sweeps. Combustion
Dhotre, Akash, Voris, Alex, Okey, Nathan, Kane, Seamus, Northrop, William
Technical Paper
Overview of Indian Government Policies, Regulations and Automotive Company Strategies toward Net-zero Emissions2025-01-0184To be published on 06/16/2025
The automotive sector in India is undergoing a transformation, driven by government policies and regulations aimed at achieving net-zero carbon emissions. In alignment with global climate goals, the Indian government has set ambitious targets to reduce greenhouse gas emissions, with a focus on promoting Electric Vehicles (EVs) and Hydrogen Fuel Cell Vehicles (FCVs). Initiatives like the Faster Adoption and Manufacturing of Hybrid and Electric Vehicles (FAME) Scheme, along with tax incentives, subsidies, and charging infrastructure development, are designed to accelerate the adoption of cleaner vehicles. The introduction of stricter emission standards and the National Electric Mobility Mission Plan (NEMMP) further underscores the push toward sustainable mobility. In response, Indian automotive companies are shifting strategies to align with these government directives. Major players are significantly increasing investments in EV technology, focusing on enhancing battery performance
Patil, Nikhil Nivrutti, Saurabh, Saurabh, Bhardwaj, Rohit, Gawhade, Ravikant, Gadve, Dhananjay, Amancharla, Naga Chaithanya
Technical Paper
Techno-Economic Analysis of an Integrated E-Methanol Production Plant Utilizing First and Second Generation Biomass Resources2025-01-0182To be published on 06/16/2025
Building upon foundational research utilizing Aspen Plus modeling for e-methanol production from sugar cane and sugar beet biomass, this study advances by incorporating a comprehensive techno-economic assessment (TEA) of an integrated e-methanol production system. The established integrated system converts biomass into ethanol through fermentation and synthesizes e-methanol using both captured CO2 and syngas derived from biomass residue gasification. The approach optimizes dual utilization of CO2 and biomass thereby fostering a circular carbon economy. The TEA quantifies capital expenditures (CAPEX), operational expenditures (OPEX), and levelized costs of energy (LCOE), providing a detailed economic analysis of the potential for commercializing e-methanol. Additionally, a sensitivity analysis is conducted to evaluate the impact of variable factors such as feedstock prices, process yields, and energy costs on the economic outcomes. This sensitivity analysis is crucial for understanding
Fernandes, Renston Jake, Shakeel, Mohammad Raghib, Nguyen, Ducduy, Im, Hong G., Turner, James W.G.
Technical Paper
Research on Combustion Characteristics of Flash-Boiling Spray in Cylinders Based on Machine Learning Methods2025-01-0205To be published on 06/16/2025
With the increasing number of vehicles in operation, exhaust emissions from engines have exerted negative impacts on ecological environments, prompting researchers to actively pursue cleaner and more efficient in-cylinder combustion strategies. Flash-boiling spray technology, capable of generating superior fuel atomization under relatively low injection pressures, has emerged as a promising approach for achieving performance breakthroughs in gasoline direct injection (GDI) engines. While current research primarily focuses on morphological characterization and mechanistic analysis of flashboiling spray, there remains insufficient understanding of flame development characteristics under flash boiling spray conditions within engine cylinders. This study systematically investigates the combustion characteristics of TPRF and PRF fuels under both subcooled and flash-boiling spray conditions through the integration of image processing and machine learning methodologies. Experimental
Zhang, Weixuan, Shahbaz, Muhammad, Cui, Mingli, Li, Xuesong, Xu, Min
Technical Paper
Effect of Ignition Condition and Fuel Octane Number on Knock Intensity in a Small 2-Stroke Engine2025-01-0211To be published on 06/16/2025
The internal combustion engines are widely used on automotive transportation for its high energy storage system efficiency and economic benefits. The 4-stroke engine has dominated all other forms to date, because the Otto cycle is simpler to comprehend. However, the significant benefits such as, less pumping work and friction, lighter construction of 2-stroke engine, helped with applications which appreciate the simplicity and power density as well as meet the emission regulations. The disadvantages of the 2-stroke engine mainly caused by the lack of sufficient scavenging process, which limited its trapping efficiency. Also, the overlap of the intake and exhaust phases results in charge short-circuiting, more fuel consumption and high unburned hydrocarbon emissions. For the reason above, it is difficult for 2-stroke engines to realize stoichiometric combustion and unable to use three-way catalyst to control emissions. The residual exhaust gas in the cylinder makes the spark ignition
Liu, Jinru, Yamazaki, Yoshiaki, Otaki, Yusuke, Kato, Hayato, Yokota, Takumi, Iijima, Akira
Technical Paper
Effects of Double Injection Strategy in a Diesel-Ammonia Dual-Fuel Engine2025-01-0206To be published on 06/16/2025
This study investigates the application of a double injection strategy in a single-cylinder marine diesel-ammonia dual-fuel engine retrofitted for experimental analysis. Diesel micro-pilot (MP) injection was used to ignite ammonia combustion, with diesel and ammonia injected separately into the cylinder through dedicated injectors. The first MP injection timing was fixed at -20 CAD before ammonia injection timing, and both early and late double MP injection strategies were implemented to evaluate their effects on ammonia combustion, engine performance, and exhaust emissions. Under all conditions, the ammonia injection timing remained constant. Early double injection strategies, with the second MP injection occurring before the first, enhanced premixed diesel combustion by raising in-cylinder temperature and pressure. However, this early heat release was ineffective for ammonia evaporation and combustion due to poor timing alignment. In contrast, late double injection strategies, with
Park, Chansoo, Jang, Ilpum, Park, Cheolwoong, Kim, Minki, Park, Gyeongtae
Technical Paper
Residual Gas and Emission Characteristics in a Propane-Fueled Spark-Ignition Engine with Varying Combustion Durations2025-01-0202To be published on 06/16/2025
This research investigates the impact of combustion duration on combustion characteristics, emissions, and residual gas in a propane-fueled spark ignition engine under varying engine speeds. Using a two-cylinder V-twin engine and AVL-Boost simulation, experiments were conducted at speeds ranging from 3000 to 8000 rpm with combustion durations between 40° and 80° crank angle. The study integrates simulation and experimental methods to address challenges in measuring residual gas and effective release energy (ERE) under different conditions. Results show that longer combustion durations generally lead to increased residual gas and BSFC, while also influencing peak fire temperature, effective release energy, and emission characteristics. At 3000 rpm, optimal conditions were observed with a peak BMEP of 11.11 bar, torque of 25.01 Nm, power output of 14.87 kW, and a minimum BSFC of 311.43 g/kWh. Longer combustion durations elevated the residual gas, reaching up to 0.946 at 8000 rpm, and
Quach, Nhu Y, Lim, Ocktaeck
Technical Paper
Analysis of Combustion Characteristics of a Small 2-Stroke Opposed Piston Engine Using an Optically Accessible Engine and Numerical Analysis2025-01-0223To be published on 06/16/2025
As global warming becomes more serious, decarbonization of internal combustion engines, which emit a large amount of carbon dioxide, is being promoted. It is predicted that many vehicles will still be equipped with engines in 2035, and a variety of powertrains will be required in the future. Therefore, we focused on the opposed-piston engine as an internal combustion engine specialized for power generation applications. The opposed-piston engine is characterized by its light weight due to the absence of a cylinder head, low S/V ratio due to the ultra-long stroke, reduced cooling loss due to the long stroke, and reduced vibration due to the offsetting of the reciprocating inertial forces of the left and right pistons. We believe that the engine for power generation can achieve the required high efficiency operation and vibration reduction. Therefore, in this study, combustion analysis of a two-stroke opposed-piston engine with features of low vibration, high efficiency, and high output
Yamazaki, Yoshiaki, Watanabe, Sou, Okawara, Ikumi, Otaki, Yusuke, Liu, Jinru, Iijima, Akira
Technical Paper
Development of After-treatment Systems and Control Strategy for a Hybrid-dedicated Homogeneous Lean Burn Engine2025-01-0217To be published on 06/16/2025
Lean-burn gasoline engines can improve fuel economy thanks to the higher specific heat ratio of the mixture and the reduced cooling loss during the combustion process. In addition, when combined with hybrid technology, the technology can achieve more synergies by overcoming obstacles such as limited operating conditions. However, the challenge of this technology is to reduce exhaust emissions to a level suggested by future stringent regulations. In lean-burn gasoline engines, nitric oxide (NOx) emissions are difficult to convert using conventional three-way catalysts (TWCs). Therefore, developing an effective NOx after-treatment system has been a key technology in the development of lean-burn engines. In addition, hydrocarbon (HC) emissions are also challenging because they increase under lean combustion conditions, while the lower exhaust temperature under lean conditions makes them hard to oxidize. Therefore, a catalyst technology capable of effectively converting HC, even at a low
Oh, Heechang, Lee, Jonghyeok, Sim, Kiseon, Lim, SeungSoo, Park, Jongil, Park, Minkyu, Kang, Hyunjin, Han, Donghee, Lee, Kwiyeon, Song, Jinwoo
Technical Paper
Thermal efficiency improvement and emission reduction of methanol spark ignition engine using lean-burn strategy2025-01-0224To be published on 06/16/2025
Methanol is a promising fuel for achieving carbon neutrality in the transportation sector, particularly for internal combustion engine vehicles. With its high-Octane number, methanol enables higher thermal efficiency compared to gasoline engines. Additionally, its wide flammability range allows stable engine operation under lean burn conditions at low to mid-load levels. In this study, experiments were conducted on a single-cylinder engine to examine the combustion and emission characteristics under varying excess air ratios and injection timings. The results showed that the highest thermal efficiency was achieved at the highest excess air ratio, despite the lowest combustion efficiency and the longest burn duration. This outcome highlights that a larger air mass reduces heat loss and pumping loss. Furthermore, NOx emissions decreased due to the reduction in in-cylinder temperatures. However, HC emissions increased as a result of the decline in combustion efficiency
Lee, Seungwon, Kim, Hyunsoo, Hwang, Joonsik, Bae, Choongsik
Technical Paper
Understanding how blending different ratios of renewable fuels with diesel impacts the toxicity of exhaust particulates to human health.2025-01-0207To be published on 06/16/2025
The urgent need to decarbonise transport has increased the utilisation of renewable fuels with current hydrocarbons. Heavy duty vehicle electrification solutions are yet to be realised and therefore the reliance on diesel engines may still be present for decades to come. Currently, the diesel supplied to fuel stations across the UK is a 7% blended biodiesel, whilst in South Korea a 5% blend is utilised. Biodiesel is produced from renewable sources for example; crops, waste residue and oils or biomass. Particulates from diesel combustion are known to be toxic, due to the presence of polyaromatic hydrocarbons (PAHs) however there is very limited understanding of blending oxygenated fuels on the toxicity of the particulates produced. PAHs are aromatic structures that can be metabolised into chemicals which can disrupt DNA replication and potentially influence cancer mechanisms if inhaled in high quantities. Soyabean methyl-ester (SME) was blended at lower ratios, e.g., 5%, 10%, 15% and
Hailwood, Emma, Hellier, Paul, Ladommatos, Nicos, Leonard, Martin
Technical Paper
Investigating lubricants base oils reactivity in ammonia/hydrogen engines via accelerated aging2025-01-0240To be published on 06/16/2025
As a carbon-free molecule, ammonia is more and more considered as a relevant fuel for long distance and off-road applications. However, this gas has different combustion characteristics compared to conventional fuels, challenging the suitability of lubricants to such engines. In this work, the evolution of lubricants under conditions mimicking ammonia combustion was assessed. Mineral and polyester lubricant base oils were exposed to oxygen, nitrogen oxides, and ammonia in a pressurized reactor under stirring. Oil aliquots were sampled at regular intervals, and characterized using Fourier Transform Infrared Spectroscopy (FTIR), viscosity and total oxygen and nitrogen contents measurements. Exposure to air containing nitrogen oxides resulted in quicker accumulation of oxidation products compared to neat air, for both the mineral and complex polyester base oil. Besides, exposure to gaseous ammonia in air resulted in a slower oxidation rate for both oils, compared to neat air. A global
Doncoeur, Carole, Giarracca, Lucia, Cologon, Perrine, Rousselle, Christine
Technical Paper
An Experimental Study on Aqueous Ammonia and Diesel Dual-Fuel Combustion with Ignition Improving Additives in a Compression Ignition Engine2025-01-0231To be published on 06/16/2025
Ammonia is a potential vector of renewably produced hydrogen for combustion systems and decarbonisation of transport. However, anhydrous ammonia remains dangerous and difficult to handle due to its volatility and toxicity. Therefore, a water-based solution of ammonium hydroxide (NH4OH) was proposed to investigate the potential use as a fuel in a compression-ignition engine. Ammonium hydroxide, also referred to as aqueous ammonia, is liquid phase under atmospheric conditions; therefore, the storage of such a fuel does not require high pressure. Previous work has established that ammonium hydroxide solution could contribute to energy release during co-combustion with fossil diesel. However, the presence of water reduced combustion stability and limited the extent to which aqueous ammonia could displace diesel. In addition, the characteristics of pollutant emissions of burning such a fuel remained less understood. This study therefore explores the potential of ignition improving additives
Han, Yanlin, Hellier, Paul, Schonborn, Alessandro, Ladommatos, Nicos
Technical Paper
A Comparative Assessment of Port Fuel Injection and Direct Injection of Hydrogen in Internal Combustion Engines: Performance, Efficiency, and Emissions2025-01-0239To be published on 06/16/2025
With the transition toward low-carbon fuels-based transportation systems, hydrogen is becoming increasingly promising as a sustainable internal combustion engine (ICE) fuel. There are two pathways for introducing hydrogen: Port Fuel Injection (PFI) and Direct Injection (DI) in an engine, which greatly affects performance, efficiency, and emissions. In the Port Fuel Injection (PFI); hydrogen is introduced into the intake manifold and mixed with air before reaching the combustion chamber. This approach is preferred due to its affordability, ease of use, and compatibility with current engine configurations. Because of PFI's more uniform air-fuel mixture, combustion is smoother, and NOx emissions are reduced. On the other hand, it raises the possibility of pre-ignition, particularly when engine loads are high, and a decrease in volumetric efficiency due to a reduction in the volume of intake air as hydrogen replaces it. Direct injection gives exact control over the timing and volume of
Ahirwar, Sachin, Kumar, Naveen
Technical Paper
Combustion and emission characteristics of marine Ammonia-Diesel dual fuel single-cylinder engine with MP injector change2025-01-0235To be published on 06/16/2025
Recently, as regulations on greenhouse gas emissions due to global warming have tightened, there has been growing interest in engines that use environmentally friendly fuels. In this context, ammonia is gaining attention as a potential alternative to fossil fuels in the future. However, due to the unique fuel characteristics of ammonia compared to traditional fuels, research is being conducted on using diesel as an ammonia ignition source. In this study, combustion and exhaust characteristics were compared according to the characteristics of micro-pilot diesel injectors in the marine ammonia-diesel dual fuel single-cylinder engine. Various injectors with different hole numbers and sizes were examined (Injector A: more holes and larger size, Injector B: fewer holes and smaller size). To maintain a constant energy ratio between ammonia and diesel at a steady load, the injection duration was adjusted, and the MP injection timing varied in 5 CAD intervals to evaluate performance and
Jang, Ilpum, Park, Cheolwoong, Kim, Minki, Park, Chansoo, Kim, Yongrae, Park, Gyeongtae, Lee, Jeongwoo
Technical Paper
Impact of reduced catalytic activity on passive regeneration of catalyzed diesel particulate filters2025-01-0185To be published on 06/16/2025
Oxidation catalysts can greatly improve the regeneration efficiency of diesel particulate filters (DPF) by providing sufficient levels of NO2 for low-temperature soot oxidation. As for other automotive catalysts, catalyzed DPFs (CDPFs) are subject to aging effects, resulting in decreased performance of the NO oxidation reaction. The life span of CDPFs generally only considers the elevated back pressure as a consequence of the accumulation of ash. However, with reduced catalytic activity and impaired functionality of the regeneration process there is a risk of premature replacement of the CDPF or accumulation of soot above critical levels. In this study, a new exhaust aftertreatment system has been developed to accommodate sub-scale catalysts and DPFs for testing with full-size heavy-duty engines. The modified exhaust aftertreatment system was used together with a rig for accelerated soot and ash loading to assess the impact of CDPF aging on regeneration performance under real
af Ugglas, Samuel, Finker, Pascal, Ersson, Anders, Yao, Dawei, Pettersson, Lars J., Kusar, Henrik
Technical Paper
Catalyzing the Hydrogen Economy: Designing Low-Cost Refueling Modules for India's Mobility Revolution2025-01-0187To be published on 06/16/2025
The likely depletion of fossil fuel reserves in the next fifty years and growing environmental concerns caused by petroleum fuel-based vehicles highlight the urgent need for sustainable alternatives. India, a developing country, requires a significant amount of energy to sustain its growth, most of which is imported. Hydrogen is one of the cleanest fuels and offers sustainable pathways to a low-carbon future. The government of India has already launched a Green Hydrogen mission and has set up a very ambitious target for 2030. However, the absence of adequate refueling infrastructure is a significant blockade to India's widespread adoption of hydrogen-powered vehicles. The mobile hydrogen refueling station (MHRS) is a flexible system that enables lower initial capital costs than fixed hydrogen refueling stations and allows for the gradual build-up of hydrogen mobility fleets. Such a system could be very useful in India, and it integrates advanced safety features, including hydrogen leak
Mathur, Animesh, Nayak, Ajay, Kumar, Naveen
Technical Paper
Development of Simple Models for Performance Estimation of a Spark Ignition Engine Fueled with Ammonia and Hydrogen2025-01-0238To be published on 06/16/2025
Achieving a carbon neutral society, eliminating greenhouse gas emissions is one of the most important issues. Ammonia is expected as a carbon free energy source. However, the laminar burning velocity of ammonia is much slower than hydrocarbons. Then, it is common to reform a portion of ammonia and use the ammonia/hydrogen mixture as a fuel. In this research, the operating characteristics of spark-ignition engine fueled with ammonia reformed gas is investigated and construct model estimating engine performance. A four-stroke single cylinder spark-ignition engine with a stroke volume of 212 cm3 is used. Total equivalence ratio is kept at unity and ammonia equivalence ratio is changed. Also, ammonia reformed gas is simulated as follows: ammonia and hydrogen are supplied from high pressure cylinders and injected by using automobile gaseous fuel injectors. Nitrogen is supplied from high pressure cylinder and supplied 1/3 of the molar ratio to hydrogen by a mass flow controller. The test
Ichikawa, Aya, Ogura, Yuto, Yanaoka, Kazuki, Gonzalez Palencia, Juan, Kambara, Shinji, Araki, Mikiya
Technical Paper
numerical investigation into the combustion and emission characteristics of ammonia direct injection mechanism2025-01-0241To be published on 06/16/2025
Ammonia is an attractive option because of its relatively low greenhouse gas (GHG) emissions, high energy density, competitive cost, and ubiquitous infrastructure for manufacturing, storage, and distribution. In this work, the optimum combustion characteristics are investigated to propose an efficient ammonia engine for future investigation. The effects of ammonia addition on diesel combustion characteristics were numerically investigated in a CI engine. The investigation was conducted by structured 3D CFD modeling to analyze the combustion characteristics. The validation of the boundary condition was compared to the designed experimental ammonia engine. The direct injection timing of 10o-50oBTDC and injection pressure 300-800 bar was proposed to identify the optimum autoignition characteristics. The equivalence ratios 1, 0.75, 0.5, and 0.25 were used in order to analyze the high cetane number characteristics and the air-fuel ratio.
Setiawan, Ardhika, Lim, Ocktaeck
Technical Paper
Evaluating the Impact of Displacing Injected Gasoline with Aspirated Ammonia in a Direct Injection Spark Ignition Engine2025-01-0226To be published on 06/16/2025
Replacing fossil fuels with renewable ammonia could provide a crucial step towards the decarbonisation of transport sectors. However, many challenges remain in utilising ammonia within combustion systems: the volumetric energy density of ammonia is significantly lower than that of gasoline, exposure to ammonia (including ammonia slip) can be detrimental to human health, and the production of emissions, including unregulated emissions (such as N2O), from ammonia combustion can be catastrophic for the environment if not treated appropriately. Therefore, there is a need to determine the efficacy of ammonia as a fuel for internal combustion engines and the impact on the efficiency of energy release and the resulting exhaust emissions. A modern spark ignition engine was modified such that ammonia was aspirated through the engine intake air to incrementally displace engine gasoline and maintain a constant work output. It was found that displacing the fuel energy supplied by direct injected
Sivaranjitham, Annaniya Mitchell, Hellier, Paul, Ladommatos, Nicos, Millington, Paul, Alcove Clave, Silvia
Technical Paper
Life Cycle Assessment of Hydrogen Generation through Steam Methane Reforming: A Focus on Co-Product Allocation between Steam and Electricity2025-01-0181To be published on 06/16/2025
This research presents a numerical analysis of the environmental impacts associated with using hot steam as a co-product in hydrogen production through Steam Methane Reforming (SMR) of renewable gas sources. As hydrogen production technology advances rapidly, reducing emissions and addressing environmental concerns, particularly greenhouse gas (GHG) emissions, have become essential. This study examines the SMR process with a focus on the environmental effects of utilizing hot steam as a co-product for electricity generation or facility heating. The analysis evaluates renewable feedstocks, including landfill gas, animal waste, food waste, and wastewater sludge, to determine their viability for sustainable hydrogen production. Key pollutants, such as carbon monoxide and nitrogen oxides, along with GHGs, are assessed to identify the most environmentally advantageous feedstock options. This work aims to provide insights promote sustainable hydrogen production practices.
Rosyadi, Ahmad Adib, Lim, Ocktaeck
Technical Paper
Assessing the Performance of a Modified Fuel Injection System–Equipped Dimethyl Ether-Fueled Genset/Tractor Engine04-18-03-001405/21/2025
Ethers are emerging as suitable mineral diesel replacements. A customized mechanical fuel injection system was used to investigate the dimethyl ether–fueled genset/tractor, and ~75% rated engine load was achieved over diesel. The in-cylinder pressure rise rate was about half for the dimethyl ether engine. However, the lower pressure generated in the high-pressure dimethyl ether line reduced brake thermal efficiency for the dimethyl ether engine. Dimethyl ether engines emitted lower nitrogen oxide emissions than baseline diesel except at higher loads and reduced nozzle opening pressure. Carbon monoxide emissions increased due to prolonged and incomplete combustion at higher loads with reduced nozzle opening pressure. Blowby gas leakage was lower for dimethyl ether than for baseline diesel engines. Overall, the genset/tractor engine could perform satisfactorily using a customized fuel injection system and will help achieve carbon neutrality from the various sectors using this technology.
Agarwal, Avinash Kumar, Pal, Manojit, Valera, Hardikk
Journal Article
Development of an Intelligent Instrumented Tire for Real-Time Hydroplaning Risk Estimation10-09-03-002705/21/2025
This study introduces an innovative intelligent tire system capable of estimating the risk of total hydroplaning based on water pressure measurements within the tread grooves. Dynamic hydroplaning represents an important safety concern influenced by water depth, tread design, and vehicle longitudinal speed. Existing intelligent tire systems primarily assess hydroplaning risk using the water wedge effect, which occurs predominantly in deep water conditions. However, in shallow water, which is far more prevalent in real-world scenarios, the water wedge effect is absent at higher longitudinal speeds, which could make existing systems unable to reliably assess the total hydroplaning risk. Groove flow represents a key factor in hydroplaning dynamics, and it is governed by two mechanisms: water interception rate and water wedge pressure. In both the shallow water and deep water cases, the groove water flow will increase as a result of increasing the longitudinal speed of the vehicle for a
Vilsan, Alexandru, Sandu, Corina, Anghelache, Gabriel, Warfford, Jeffrey
Journal Article
Methodology for Selection of Gasoline Catalytic Convertor & Oxygen Sensor Position, Study on Oxygen Storage Capacity for 1.2L Turbocharger MPFI Engine2025-01-502205/16/2025
The results published in this paper emphasize on the study of three-way catalytic convertor for a 1.2 L turbocharged multi-point fuel injection gasoline engine. This paper takes us through the findings on methodology used for finalizing the brick configuration for catalytic convertor along with downstream oxygen sensor placement for emission control and methods applied for catalytic convertor selection with actual testing. The advantages of dual brick configuration over single brick with downstream sensor placed in between the bricks to enable faster dew point of sensor is explained using water splash test and design confirmation of better exhaust gas flow vortices concentration at the sensor tip for better sensing. Selection of catalytic convertor loading by testing its emission conversion capability and light-off behavior. NOx conversion capability across stoichiometric ratio (14.7:1 for petrol) on selected most operational zone was tested (±5% lambda) for the design-finalized
Arun Selvan, S. A., Paul, Arun Augustine, Selvaraj, Manimaran
Technical Paper
Experimental Investigation of Carbon Nanotube Additives Effect on Performance and Emission of a High-Injection Pressure Common Rail Diesel Engine03-18-03-002005/16/2025
Due to the continuous decrease in fossil fuel resources, and drawbacks of some biofuel properties, in addition to restricted environmental concerns, it becomes a vital manner to innovate some approaches for energy saving and emission reduction. One of the promising approaches is to enhance the fuel properties via adding nanoparticles. Carbon nanotubes (CNTs) blended with biofuels get extensive investigations by researchers using conventional diesel engines at relatively limited operating regimes. The objective of this work is to extend these studies using diesel fuel, rather than biofuels, on a high-injection pressure (1400–1600 bar) common rail diesel engine at wide operating conditions and higher CNT concentrations. Experimental results show an increase in peak pressure up to 24.46% than pure diesel when using 100 ppm CNTs concentration. Also, BSFC has decreased by 33.19%, and BTE increased by 54.2% compared to pure diesel fuel at high speeds and loads. NOx and CO2 emissions raised
Moaayet, Sayed, Neseem, Waleed Mohamed, Amin, Mohamed Ibrahim, Shahin, Motasem Abdelbaky
Journal Article
Gas Turbine Engine Performance Presentation and Nomenclature for Object-Oriented Computer ProgramsARP5571D (Current)05/16/2025
This document provides recommendations for several aspects of air-breathing gas turbine engine performance modeling using object-oriented programming systems. Nomenclature, application program interface, and user interface are addressed with the emphasis on nomenclature. The Numerical Propulsion System Simulation (NPSS) modeling environment is frequently used in this document as an archetype. Many of the recommendations for standards are derived from NPSS standards. NPSS was chosen because it is an available product. The practices recommended herein may be applied to other object-oriented systems. While this document applies broadly to any gas turbine engine, the great majority of engine performance computer programs have historically been written for aircraft propulsion systems. Aircraft and propulsion terminology and examples appear throughout.
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
Recommended Practice
Experimental Quantitative Analysis of Spray Velocity Field Characteristics of Four Compression-Ignition Engine Oxygenated Alternative Fuels03-18-03-002105/10/2025
As the suitable substitutes for diesel in compression-ignition (CI) piston engines, hydrotreated vegetable oil (HVO), polyoxymethylene dimethyl ethers (PODEs), and bio-aviation fuel (BAF), among other oxygenated alternative fuels have been widely recognized due to higher cetane values. To explore the in-cylinder fuel spray dynamics and subsequent fuel–air entrainment of these fuels, experimental studies on near-field and full-field spray characteristics were carried out by the diffuser back-illumination imaging (DBI) method within a constant-volume chamber. The local velocity was inferred by momentum flux conservation and Gaussian radial profile assumption, and the dimensionless Jet number was introduced to qualify the strength of interaction within two-phase flow. It was found that the initial spray transitions from a “needle” to a larger spray head structure as injection pressure rises, especially with PODE3-5 exhibiting a stable “mushroom” structure due to its higher surface tension
Chen, Houchang, Jiang, Junxin, Hu, Yong, Yu, Wenbin, Zhao, Feiyang
Journal Article
Sustainable Design of Automotive Batteries2025-01-000105/08/2025
A consequence of the automotive industry's shift to electrification is that a significantly higher percentage of a vehicle's lifecycle CO2 emissions occur during the production phase. As a result, vehicle manufacturers and suppliers must shift the focus of product development from the 'in-use phase only' to optimizing the complete product lifecycle. The proper design of a battery has the highest impact to all other phases following in the life cycle. It influences the selection of materials, the manufacturing, in-use and end of life, respectively the recycling and recycling yield for a circular economy. Using real-life examples, the paper will explain what the main parameters are necessary for designing a sustainable battery. What are the low hanging fruits to be considered? In addition, it will elaborate on the relation as well as the impacts to other KPIs like safety, costs and lifetime of the battery. Finally, it will round up in an outlook on how batteries will evolve in the future
Braun, Andreas, Rothbart, Martin
Technical Paper
Study on the Aspiration Properties of Glassrun Seal System under Time-Varying Pressure Difference2025-01-003005/05/2025
When a vehicle is driven at high speed, there exists intricate flow pattern and vortex shedding at the side window area with intense pressure fluctuation. A significant dynamic pressure difference between the vehicle's exterior and interior can render the side window sealing system vulnerable to aspiration. This susceptibility can lead to the generation of leakage noise, adversely affecting acoustic comfort in the vehicle's cabin. This paper delves into the aspiration properties of glassrun seal system under time-varying pressure difference. A nonlinear finite element model of the glassrun seal was established to simulate the quasi-static deformation of the sealing strip during installation process, which aims to obtain the deformed geometric shape and residual stress after this process. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of
Li, Hanqi, He, Yinzhi, Zhang, Lijun, Zhang, Yongfeng, Yu, Wuzhou, Jiang, Zaixiu, Blumrich, Reinhard, Wiedemann, Jochen
Technical Paper
Sound Design for Electric Vehicles: Enhancing Safety and User Experience Through Acoustic Vehicle Alerting System (AVAS)2025-01-006805/05/2025
Silent motors are an excellent strategy to combat noise pollution. Still, they can pose risks for pedestrians who rely on auditory cues for safety and reduce driver awareness due to the absence of the familiar sounds of combustion engines. Sound design for silent motors not only tackles the above issues but goes beyond safety standards towards a user-centered approach by considering how users perceive and interpret sounds. This paper examines the evolving field of sound design for electric vehicles (EVs), focusing on Acoustic Vehicle Alerting Systems (AVAS). The study analyzes existing AVAS, classifying them into different groups according to their design characteristics, from technical concerns and approaches to aesthetic properties. Based on the proposed classification, an (adaptive) sound design methodology, and concept for AVAS are proposed based on state-of-the-art technologies and tools (APIs), like Wwise Automotive, and integration through a functional prototype within a virtual
Rodrigues Ferraz Esteves, Ana Raquel, Campos Magalhães, Eduardo Miguel, Bernardes de Almeida, Gilberto
Technical Paper
Comprehensive Analysis and Optimization of Door Closing Sound Quality of a Heavy Truck2025-01-006605/05/2025
Based on the objective and subjective experiment and finite element analysis, the influencing factors on the door closing sound quality of a heavy truck is analyzed and optimized. Results show that the loudness and sharpness can be reduced by increasing stiffness and damping of the door. The sound quality can be enhanced by increasing the pressure release area, which can decrease the air pressure resistance of dooring closing. By adding holes on the inner liner and changing the pressure release location, the dooring closing air pressure resistance is reduced from 289 Pa to 181 Pa. In terms of the rebound sound, the sound level is positively related to the door closing force. Increasing the protrusion height and decreasing the stiffness of the vibration absorber of the handle can improve the rebound sound quality. Optimizing the absorbers on both ends of the handle and adding damping material can decrease the loudness by 47.8%, reduce the cavity sound, reduce the rattle and improve the
Wang, Jian, Zhang, Yongshen, Feng, Lei, Xie, Chenhao, Lin, Jiewei, Sun, Changchun
Technical Paper
Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis2025-01-005805/05/2025
To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.
Yang, Wenlong, Melo, Andre
Technical Paper
Simulation of Pass-by Fan Noise Emissions and Advancing Test Regulations for Heavy-Duty Electric Vehicles2025-01-008605/05/2025
The rapid adoption of electric vehicles (EVs) necessitates updates to the automotive testing standards, particularly for noise emission. This paper examines the vehicle-level noise emission testing of a Nikola Class 8 hydrogen fuel cell electric semi-truck and the component-level noise emission testing needed to create a predictive simulation model using Wave6 software. The physical, component-level noise emission testing focused on individual cooling fans in a semi-anechoic chamber to assess their isolated noise contributions. With this data, an initial model was developed using spatial gradient statistical energy analysis, which successfully predicted pass-by noise levels based on varying fan locations and speeds. Real-world pass-by testing confirmed the model's accuracy across different cooling fan speeds. By leveraging advanced simulation techniques, engineers aim to enhance the accuracy and reliability of pass-by noise predictions through cost-effective studies of architectural
Passador, Stephen, Woo, Sangbeom, Liu, Ting-Wei, De La Vega Alonso, Gerardo, Kim, James
Technical Paper
Acoustic Evaluation of Fiber-Based Materials for Engine Bay Applications2025-01-011505/05/2025
A newly formulated fiber-based material was developed to offer a sustainable alternative to foam-based vehicle acoustic products. The fiber-based material was designed to be used in multiple vehicle acoustic applications, with different blends of the material available depending on the application. It performs well as an engine bay sound absorber due to its high heat tolerance and good absorption performance. A study was conducted to evaluate the sound absorption performance of this fiber-based material, specifically the engine bay blends, in comparison to that of current foam-based products. The results from this study show that the sound absorption performance of this new fiber-based material can match that of current foam-based materials while providing a sustainable and fully recyclable product, unlike the foam.
Krugh, Jack
Technical Paper
Experimental Analysis of Pressure Pulsation Noise Phenomenon in a CNG-Powered Passenger Vehicle2025-01-011205/05/2025
Compressed Natural Gas (CNG) engines are emerging as a viable alternative to gasoline and diesel in heavy commercial and passenger transport worldwide. They offer reduced CO₂ emissions and support energy independence in regions rich in natural gas. In India, enhanced CNG infrastructure and strict emission regulations have driven OEMs to develop CNG vehicles across all segments. Moreover, from a noise and vibration standpoint, CNG vehicles are expected to deliver cabin refinement comparable to that of their fossil fuel counterparts. However, one of the major challenges associated with CNG vehicles is the excitation due to additional components like CNG Pressure Regulator, Injector et al. The operational metallic/pulsation noises are generally higher as compared to liquid fuels like gasoline due to dry nature of the CNG fuel. This paper describes in detail the pulsation noise phenomena encountered during one of the late-stage vehicle development projects. An experimental root cause
Chatterjee, Joydeep, Ravindran, Mugundaram
Technical Paper
Experimental Investigation into Modulated Aeroacoustic Cabin Noise Arising from Unsteady Flow Conditions2025-01-002905/05/2025
The unsteady wind conditions experienced by a vehicle whilst driving on the road are different to those typically experienced in the steady-flow wind tunnel development environment, due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. This paper presents an experimental approach using a large SUV-shaped vehicle to assess the effect of unsteady wind on the modulated noise performance, commonly used to evaluate unsteady wind noise characteristics. The contribution from different geometric modifications were also assessed. The approach is extended to assess the pressure distribution on the front side glass of the vehicle, caused by the aerodynamic interactions of the turbulent inflow in straight and yawed positions, to provide insight into the noise generation mechanisms and differences in behaviour between the two environments. The vehicle response to unsteady wind
Jamaluddin, Nur Syafiqah, Oettle, Nicholas, Staron, Domenic
Technical Paper
Tonal Noise Investigation of Automotive HVAC Systems: A Hybrid Method2025-01-002705/05/2025
There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the frontline of noise emissions inside the car cabin. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective, based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low tonal noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the
Bennouna, Saad, Alaoui, Mohamed, Henner, Manuel
Technical Paper
Pass-by Noise Contribution Analysis of an Agricultural Tractor2025-01-013405/05/2025
There is an increasing effort to reduce noise pollution across different industries worldwide. From a transportation standpoint, pass-by regulations aim to achieve this and have been implementing increasingly stricter emissions limits. Testing according to these standards is a requirement for homologation, but does little to help manufacturers understand why their vehicles may be failing to meet limits. Using a developed methodology such as Pass-by Source Path Contribution (SPC, also known as TPA) allows for identification of dominant contributors to the pass-by receivers along with corresponding acoustic source strengths. This approach is commonly used for passenger vehicles, but can be impractical for off-highway applications, where vehicles are often too large for most pass-by-suitable chassis dynamometers. A hybrid approach is thereby needed, where the same techniques and instrumentation used in the indoor test are applied to scenarios in an outdoor environment. This allows for
Freeman, Todd, Engels, Bret, Thuesen, Ben
Technical Paper
Items per page:
1 – 50 of 41777