bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Fuel Injection Pressure on Spray Characteristics of Diesel-Diethyl Ether Blends for Diesel Engine Applications: An Experimental Study
Authors: Sonawane Utkarsha , Jena Ashutosh , Agarwal Avinash Kumar
Published: April 2023

Di-ethyl ether (DEE) belongs to the family of oxygenated fuels, which have been investigated as an alternative to conventional diesel. However, increasing the proportion of DEE in DEE-diesel blends changes its physicochemical properties. This work shows the non-evaporating and non-reacting spray characteristics of diesel, DEE20 (20% v/v DEE and 80% v/v diesel), and DEE40 (40% v/v DEE and 60% v/v diesel) were investigated. The effect of fuel injection pressure (FIP: 500 and 800 bar) on the spray morphology and droplet size distribution at different axial locations along the spray axis was done. FIP of 800 bar showed a reduction in Sauter mean diameter (SMD) of spray droplets with increasing axial distance due to improved spray atomisation because of the drag forces of the surrounding air on the fuel droplets. DEE20 showed a higher number of droplets having a smaller diameter than DEE40. DEE20 and DEE40 showed superior spray atomisation characteristics than diesel. A slight increase in radial velocity was also observed with the axial location for all test fuels. DEE40 exhibited lower radial velocity compared to DEE20 and diesel. Higher fluctuation in the axial velocity of droplets was observed at an axial distance of 60 mm compared to 20 mm for diesel. This was due to increased droplet velocity distribution after the end of the injection. An increased number of smaller droplets resulted in lower jet momentum in the axial direction at the FIP of 800 bar. As a result, the average axial droplet velocity was higher at lower FIP. DEE40 showed more fluctuations amongst all test fuels, possibly due to drastic droplet diameter changes due to its superior evaporation characteristics. In this study, DEE40 at a FIP of 500 bar showed superior atomisation and evaporation characteristics. This indicated that a low-cost fuel injection system could be used for the maximum diesel replacement by DEE.
Numerical Analyses of Spray Penetration and Evaporation in a Direct Injection Engine
Authors: Wegmann Tim , Meinke Matthias , Schröder Wolfgang
Published: April 2023

Numerical analyses of the liquid fuel injection and the subsequent fuel-air mixing in a high-tumble, long-stroke direct injection engine at operation conditions of 2000 RPM are presented. The Navier-Stokes equations are numerically solved with a finite-volume method for compressible flow based on a hierarchical Cartesian mesh. The solid wall boundaries are represented by a conservative multiple cut- and split-cell method, where a semi-Lagrange level-set solver is used to track the location of the individual moving boundaries. To determine the fuel vapor before ignition, a two-way coupled large-eddy simulation of the turbulent flow field with the spray droplets is conducted. Due to the large number of spray droplets, a Lagrangian Particle Tracking (LPT) algorithm is used to predict the liquid spray penetration and evaporation. The hierarchical Cartesian mesh ensures a highly efficient usage of high performance computing platforms by applying solution adaptive mesh refinement combined with dynamic load balancing. The simulations are based on meshes with approximately 170 million cells and 1.5 million embedded spray parcels. The influence of the tumble motion on fuel distribution at the start of ignition is analyzed for several injection timings and ethanol and methanol bio-hybrid fuels. Injection at 60 CAD shows a strong influence of the fuel jets on the in-cylinder flow field and the tumble motion is deteriorated. A 7-hole modification of the spray-G injector is introduced, which shows improved fuel-air mixing by sustaining tumble motion. When methanol fuel injection is compared to ethanol, a disadvantageous fuel distribution towards the end of the compression stroke is observed, caused by the longer methanol injection duration.
Experimental Studies on the Use of Methanol-Butanol Blends in a Hot Surface Ignition Engine
Authors: Krishnan R Anoop , Elango Pradeev , Ramesh A
Published: April 2023

The property of methanol to surface ignite can be exploited to use it in a diesel engine even though its cetane number is very low. Poor lubricity of methanol is still an issue and special additives are needed in order to safeguard the injection system components. In this work a common rail three cylinder, turbocharged diesel engine was run in the glow plug based hot surface ignition mode under different injection strategies with methanol as the main fuel in a blend with n-butanol. n-Butanol was used mainly to enhance the viscosity and lubricity of the blend. The focus was on the effect of different injection strategies. Initially three blends with methanol to n-butanol mass ratios of 60:40, 70:30 and 80:20 were evaluated experimentally with single pulse fuel injection. Subsequently the selected blend of 70:30 was injected as two pulses (with almost equal mass shares) with the gap between them and their timing being varied. Finally the effect of mass share of the injection pulses was evaluated. All the experiments were done at a speed of 1800 rpm, Brake Mean Effective Pressure (BMEP) of 8 bar and injection pressure of 850 bar and performance, emissions and combustion parameters were analyzed.

Higher methanol shares increased the efficiency because of controlled combustion rates and proper combustion phasing. Enhancing the methanol share, due to its high latent heat of vaporization lowered the temperatures and the Oxides of Nitrogen (NOx) levels with near zero smoke levels. However, Hydrocarbon emission (predominantly formaldehyde and methanol) was found to be higher but it was possible to reduce it by using a diesel oxidation catalyst. Double pulse injection resulted in an improvement in the brake thermal efficiency due to better combustion phasing. Reduced the rate of pressure rise and NOx emissions were also observed. An almost equal share between the two injection pulses was found to be acceptable and the efficiency was better than the base diesel engine with negligible smoke and lower NOx levels.
Effect of Jet Ignition on Lean Methanol Combustion Using High Compression Ratio
Authors: Harrington Anthony , Hall Jonathan , Bassett Mike , Cooper Adrian
Published: April 2023

Significant reductions in vehicle carbon dioxide (CO2) emissions are required to meet fleet targets and this is increasing the interest in new combustion concepts for internal combustion engines. There is also an increased focus on the use of renewable fuels to reduce environmental impact. This study focusses on the use of methanol as an internal combustion engine fuel. Methanol is a liquid fuel that is readily produced from waste bio-matter, as well as synthetically using renewable energy, and is proposed as a primary energy vector in hard-to-decarbonise sectors, such as Marine, but could be equally applicable to road transportation.

In this study, the MAHLE Di3 engine, which is a highly boosted 3-cylinder gasoline direct injection engine capable of operating at over 30 bar BMEP, has been modified to include MAHLE Jet Ignition technology, in both passive and active configurations, as well as utilising a very high compression ratio to maximise thermal efficiency. The paper will compare the performance and emissions of the engine using a spark ignition baseline and both passive and active jet ignition configurations.

The technology combinations described enable brake thermal efficiencies of over 42% at lambda 1 and over 44% when operating lean. Measurements are presented showing thermal efficiency and engine out emissions using all three ignition technologies, relative to a gasoline baseline. It is concluded that the resulting combination of technologies, when used with methanol, represents a cost-effective route to achieving very high engine efficiency and a significant reduction in engine-out emissions compared to gasoline operation combustion engine.
Experimental and Numerical Study of a Low-Pressure Hydrogen Jet under the Effect of Nozzle Geometry and Pressure Ratio
Authors: Yeganeh Maryam , Rabensteiner Samuel , Karimkashi Shervin , Cheng Qiang , Kaario Ossi , Larmi Martti
Published: April 2023

Hydrogen (H2), a potential carbon-neutral fuel, has attracted considerable attention in the automotive industry for transition toward zero-emission. Since the H2 jet dynamics play a significant role in the fuel/air mixing process of direct injection spark ignition (DISI) engines, the current study focuses on experimental and numerical investigation of a low-pressure H2 jet to assess its mixing behavior. In the experimental campaign, high-speed z-type schlieren imaging is applied in a constant volume chamber and H2 jet characteristics (penetration and cross-sectional area) are calculated by MATLAB and Python-based image post-processing. In addition, the Unsteady Reynolds-Averaged Navier-Stokes (URANS) approach is used in the commercial software Star-CCM+ for numerical simulations. The H2 jet dynamics is investigated under the effect of nozzle geometry (single-hole, double-hole, and multiple-hole (5-hole)), which constitutes the novelty of the present research, and pressure ratio (PR = injection pressure (Pi) / chamber pressure (Pch)). The results show that the H2 jet from the single-hole nozzle possesses the fastest penetration and smallest cross-sectional area. On the contrary, the H2 jet from the double-hole nozzle possesses the slowest penetration and largest cross-sectional area. The H2 jet from the multiple-hole nozzle shows characteristics between those of the single-hole and double-hole. Overall, since higher pressure ratio and larger jet cross-sectional area lead to higher uniformity of the fuel/air mixture, high-pressure injection with the double-hole nozzle seems more advantageous to attain efficient mixing.
Challenges and Directions of Using Ammonia as an Alternative Fuel for Internal Combustion Engines
Authors: Novella Ricardo , Pastor Jose , Gomez-Soriano Josep , Bayona Javier Sánchez
Published: April 2023

In recent decades, the importance of emerging alternative fuels has increased significantly as a solution to the problems of global warming and air pollution from energy production. In this context, ammonia (NH3) is seen as a potential option and energy vector that may be able to overcome the technical challenges associated with the use of other carbon-free fuels such as hydrogen (H2) in internal combustion engines (ICE). In this research, a numerical methodology for evaluating the impact of using ammonia as a fuel for spark-ignition ICEs has been developed. A combination of a single-cylinder and multi-cylinder numerical experiments has been performed to identify the main challenges and determine correct engine configuration. In addition, the performance of the engine has been evaluated through standard homologation driving cycles, contrasting it with other alternative propulsion configurations. Finally, a simplified life cycle assessment (LCA) has been carried out to compare the global emissions with those of conventional combustion and electric technologies in the European automotive framework.
Comparative Analysis of Different Methodologies to Calculate Lambda (λ) Based on Extensive And systemic Experimentation on a Hydrogen Internal Combustion Engine
Authors: Azeem Naqash , Beatrice Carlo , Vassallo Alberto , Pesce Francesco , Davide Gessaroli , Guido Chiara , Rossi PhD Riccardo
Published: April 2023

Hydrogen Internal Combustion Engines (H2-ICEs) are subject to increased attention thanks to their extremely low criteria pollutant emission and near-zero CO2 tailpipe emissions. However, to further minimize exhaust emissions and increase the efficiency of a H2-ICE, it is important to carefully control the relative air-fuel ratio of operation, i.e. Lambda (λ), which will lead in turn to an optimal combustion process. The precise λ control mainly relies upon the methodology to calculate λ on board of the engine, where the availability of reliable sensors specifically-developed for hydrogen combustion is currently limited. In this article, a comparative analysis of different methodologies for the calculation of λ is performed, comparing four methodologies: exhaust gas analysis through a Spindt-Brettschneider approach (λEMI), raw Universal Exhaust Gas Oxygen (λR-UEGO), processed Universal Exhaust Gas Oxygen (λP-UEGO) and speed-density (λSD) outputs. The experimental data used to compare the four methodologies were acquired through detailed and systematic experimentation on a fully-instrumented single-cylinder H2-ICE. Results show that the λP-UEGO is the closest one to the reference Spindt-Brettschneider analysis λEMI and the most robust to ample variations in the nominal λ values. The sensor’s raw UEGO output λR-UEGO is instead affected by the sensor calibration which is usually performed across a range of carbon-based fuels, a procedure that introduces a bias. The results can be used for the selection of the correct methodology to calculate λ in a H2-ICE and to choose optimal sensors for mobile applications.
Auto Stop-Start Fuel Consumption Benefits
Authors: Huff Shean , Davis Stacy , Boundy Robert , Gibson Robert
Published: April 2023

With increasingly stringent regulations mandating the improvement of vehicle fuel economy, automotive manufacturers face growing pressure to develop and implement technologies that improve overall system efficiency. One such technology is an automatic (auto) stop-start feature. Auto stop-start reduces idle time and reduces fuel use by temporarily shutting the engine off when the vehicle comes to a stop and automatically re-starting it when the brake is released, or the accelerator is pressed. As mandated by the U.S. Congress, the U.S. Environmental Protection Agency (EPA) is required to keep the public informed about fuel saving practices. This is done, in partnership with the U.S. Department of Energy (DOE), through the fueleconomy.gov website. The “Fuel-Saving Technologies” and “Gas Mileage Tips” sections of the website are focused on helping the public make informed purchasing decisions and encouraging fuel-saving driving habits. In order to provide users with accurate information about the auto stop-start feature, experiments were conducted to determine its fuel economy effect. Four vehicles were tested both with and without the feature enabled under three test cycles: the Federal Test Procedure (FTP) city fuel economy test, the US06 high acceleration aggressive driving schedule that is often identified as the “Supplemental FTP” driving schedule, and the EPA New York City Cycle (NYCC). The results were compared to measure the fuel economy and consumption effects of using the auto stop-start feature. It was found that the fuel economy improvement varied significantly between drive cycles depending on the amount and percentage of idle time during the test. The largest fuel economy improvements were 7.27% and 26.4% for the FTP and NYCC, respectively.
Comparison of On-Road Highway Fuel Economy and All-Electric Range to Label Values: Are the Current Label Procedures Appropriate for Battery Electric Vehicles?
Authors: Pannone Gregory , VanderWerp Dave
Published: April 2023

As consumers transition from internal combustion engine (ICE)-powered vehicles to battery electric vehicles (BEV), they will expect the same fuel economy label-to-on-road correlation. Current labeling procedures for BEVs allow a 0.7 or higher multiplier to be applied to the unadjusted fuel economy and range values. For ICE-powered vehicles, the adjustment factor decreases with increasing unadjusted fuel economy and can be lower than 0.7. To better inform consumers, starting in 2016, Car and Driver added an on-road highway fuel-economy test, conducted at 120 kph (75 mph), that augments the performance metrics that it's been measuring since the 1950s. For electric vehicles, testing includes an evaluation of the all-electric range.

The on-road test results were aligned with the certification information for each vehicle model including unadjusted and label fuel economy and range, road load force coefficients, and labeling options. Tractive energy and kinetic energy available for regenerative braking were computed from the certification information to evaluate the differences between the on-road testing and chassis-rolls testing conducted during the certification process.

Based on these results, the highway fuel economy label tends to be a very good predictor of the fuel economy observed during the on-road test at real highway speeds with vehicles powered by an ICE. However, most BEVs tested to date fall short of both their electric consumption and range label values. For BEVs, the difference between the label and on-road consumption and range is further exacerbated by other factors, such as extreme temperatures and suggestions by automakers to charge to less than 100 percent to extend battery life. Consequently, these results support the need to re-evaluate the labeling procedures for this emerging technology as it continues to become increasingly prominent in the marketplace.
Compact Normalized Description of Vehicle Traction Power for Simple Fuel Consumption Modeling
Authors: Phlips Patrick , Ruona William
Published: April 2023

This is an extension of simple fuel consumption modeling toward HEV. Previous work showed that in urban driving the overhead of running an ICEV engine can use as much fuel as the traction work. The bidirectional character and high efficiency of electric motors enables HEVs to run as a BEV at negative and low traction powers, with no net input from the small battery. The ICE provides the net work at higher traction powers where it is most efficient. Whereas the network reduction is the total negative work times the system round-trip efficiency, the reduction in engine running time requires knowledge of the distribution of traction power levels. The traction power histogram, and the work histogram derived from it, provide the required drive cycle description. The traction power is normalized by vehicle mass, so that the drive trace component becomes invariant, and the road load component nearly invariant to vehicle mass. The resulting normalized time and work distributions form a generic compact description of a drive cycle. The round-trip efficiency of the electric powertrain then determines the large reductions in engine running time and work in urban driving. Good agreement is found with EPA data for the Toyota Camry ICEV and HEV. Additionally, as the power/weight is a largely a low order function of vehicle speed only, it provides a useful way to graphically synthesize performance requirements and vehicle capability in the same plot. The different tools are demonstrated in the analysis of a new regulatory drive test.
Design and Assessment of an Exhaust After-Treatment System Equipped with a Fuel
Authors: Rossi Vincenzo , Brocchi Luca , Medda Massimo , Paltrinieri Stefano , Rulli Federico , Tonelli Roberto
Published: April 2023

Reaching near-zero cold start emissions in a wide range of ambient conditions is a challenging, yet necessary objective. Optimizing the combustion, although fundamental to lower specific engine-out emissions, is not sufficient, especially in high-performance engines. A very high after-treatment efficiency from engine start-up onwards is mandatory. Active heating technologies allow quick heating up of after-treatment devices like a three way catalyst above their light-off temperature, regardless of engine operation. In this work, the particular characteristics of a fuel burner were analyzed. The steps that led to the design of an exhaust system equipped with a fuel burner are reported. The fuel burner ability to efficiently heat up after-treatment devices was assessed by numerical simulations and then verified experimentally. Cumulative results were compared with a passive catalyst heating strategy. The fuel burner proved effective in reducing tailpipe emissions via pre-heating, i.e. catalyst is heated before engine start.
A Multi-Function, Heated Mixer for Rapid Heat-up, Low-Temperature Ammonia Demand, Deposit Prevention and to Meet Ultra-Low NOx Regulations
Authors: Masoudi Mansour , Poliakov Nick , Noorfeshan Sahm
Published: April 2023

Selective Catalytic Reduction (SCR) operation depends strongly on both heat and ammonia availability (stored or incoming). These requirements make high efficiency SCR challenging in lower temperature cycles where SCR is relatively cold, and Diesel Exhaust Fluid (DEF) injection is largely absent due to deposit risks. Examples include low temperature cycles such as low-idling, stop-and-go or low-load cycles such as city driving or local delivery cycles.

An Electrically Heated Mixer/ EHM™ is utilized to address these challenges in a single component. EHM simultaneously provides heat for rapid SCR heat-up during the cold phase or in other low-temperature operations, steady or transient. Second, its heating mechanism makes deposit risks nearly non-existent. Third, EHM enables DEF injection at 130 °C, markedly enhancing the low temperature SCR impact. It is shown that these capabilities collectively make EHM a promising pathway for meeting ultra-stringent NOx targets including California 2027 (0.02 gr/hp.hr). Via rapidly heating the SCR catalyst during cold-start, EHM enables substantially lowering the cold-phase NOx. For instance, it is shown this lowers the cold FTP and cold WHTC NOx emission by 2 – 2.5 fold and in Low-Load Cycle by 22-fold.

EHM also allows DEF injection in low exhaust temperatures such as in 70 - 80 °C, for instance for rapidly filling the SCR catalyst with ammonia, if needed.

Unlike adding other exhaust flow heating devices where an additional component is ultimately integrated in the aftertreatment architecture, EHM is a mixer, already present in emission control systems. These flexibilities, along with its lower cost and ease in fitting, make EHM an enabling pathway for Diesel emission control systems meeting very low NOx regulations.
An Update on Continuing Progress Towards Heavy-Duty Low NO
X
and CO
2
in 2027 and Beyond
Authors: Sharp Christopher , Zavala Bryan , Neely Gary , Rao Sandesh
Published: April 2023

Despite considerable progress towards clean air in previous decades, parts of the United States continue to struggle with the challenge of meeting the ambient air quality targets for smog-forming ozone mandated by the U.S. EPA, with some of the most significant challenges being seen in California. These continuing issues have highlighted the need for further reductions in emissions of NOX, which is a precursor for ozone formation, from a number of key sectors including the commercial vehicle sector. In response, the California Air Resources Board (CARB) embarked on a regulatory effort culminating in the adoption of the California Heavy-Duty Low NOX Omnibus regulation.[1] This regulatory effort was supported by a series of technical programs conducted at Southwest Research Institute (SwRI). These programs were aimed at demonstrating technologies that could enable heavy-duty on-highway engines to reach tailpipe NOX levels up to 90% below the current standards, which were implemented in 2010, while maintaining a path towards compliance with current heavy-duty Phase 2 GHG standards. These efforts culminated in the Stage 3 Low NOX program, the results of which have been documented in previous publications.

In parallel with the completion of the Stage 3 technical effort, EPA began an effort to promulgate a national heavy-duty low NOX regulation, with the goal of completing the regulation in 2022 to support a 2027 model year implementation.[2, 3] As part of that regulatory effort, EPA leveraged the test platform that was developed under the Stage 3 program to continue investigation of Low NOX technology capabilities and limitations. The emission control system was upgraded in several ways, and a number of topics were examined that expanded the scope of the evaluation. These included investigation of system performance under a variety of field duty cycles, examination of extended useful life out to 800,000 miles, the impact of low ambient temperatures on performance, and others. The performance of the updated system, and the results of the wider system investigations are summarized in this paper.
Real-Time Simulation of CNG Engine and After-Treatment System Cold Start. Part 2: Tail-Pipe Emissions Prediction Using a Detailed Chemistry Based MOC Model
Authors: Leon de Syniawa Larisa , Siddareddy Reddy Babu , Oder Johannes , Franken Tim , Guenther Vivien , Rottengruber Hermann , Mauss Fabian
Published: April 2023

In contrast to the currently primarily used liquid fuels (diesel and gasoline), methane (CH4) as a fuel offers a high potential for a significant reduction of greenhouse gas emissions (GHG). This advantage can only be used if tailpipe CH4 emissions are reduced to a minimum, since the GHG impact of CH4 in the atmosphere is higher than that of carbon dioxide (CO2). Three-way catalysts (TWC - stoichiometric combustion) and methane oxidation catalysts (MOC - lean combustion) can be used for post-engine CH4 oxidation. Both technologies allow for a nearly complete CH4 conversion to CO2 and water at sufficiently high exhaust temperatures (above the light-off temperature of the catalysts). However, CH4 combustion is facing a huge challenge with the planned introduction of Euro VII emissions standard, where stricter CH4 emission limits and a decrease of the cold start starting temperatures are discussed.

The aim of the present study is to develop a reliable kinetic catalyst model for MOC conversion prediction in order to optimize the catalyst design in function of engine operation conditions, by combining the outputs from the predicted transient engine simulations as inputs to the catalyst model. Model development and training has been performed using experimental engine test bench data at stoichiometric conditions as well as engine simulation data and is able to reliably predict the major emissions under a broad range of operating conditions. Cold start (-7°C and +20°C) experiments were performed for a simplified worldwide light vehicle test procedure (WLTP) driving cycle using a prototype gas engine together with a MOC. For the catalyst simulations, a 1-D catalytic converter model was used. The model includes detailed gas and surface chemistry that are computed together with catalyst heat up. In a further step, a virtual transient engine cold start cycle is combined with the MOC model to predict tail-pipe emissions at transient operating conditions. This method allows to perform detailed emission investigations in an early stage of engine prototype development.
Model-Free State Estimation Using Subspace Identification and Kalman Filter
Authors: Mandloi Deepak , Sahu Prachi , Bagade Monika Jayprakash , Das Himadri
Published: April 2023

The model-based design is very much prominent in the vehicle level control system design and state estimation algorithms. It gives the edge to understand and interpret the dynamic systems. Three-way catalytic converter is a thermo-chemical device to convert the toxic oxides into carbon dioxide and water vapor, during this conversion reactions it generates the heat over the catalyst surface. Detailed chemical and thermal model of the catalyst will be able to predict the conversion efficiency, state of stored oxygen (SoX) and oxygen storage capacity (OSC). As the catalyst get aged, the reaction rates of conversion reactions deteriorate, in results the temperature dynamics also varies which wanes the exothermic heat. In this work, a novel perspective is presented to capture the behavior of SoX and health of the catalytic converter using thermal model analysis of TWC. An equivalent second order multi input single output (MISO) linear sub-space model is identified for the complex detailed thermal model. A second order MISO system is obtained using measured temperature sensor signals across the device. Recursive least square method will be updating the system parameters online then Kalman filter is employed for state estimation. Joint estimation of the hidden state is tested and validated on urban drive cycle with differently aged catalytic converters.
The Development of Engine-in-the-Loop (EIL) Testing Methodology for Front Loading Emission Investigations
Authors: Xu Zheng , Wang LinGang , Yin Haiting , Yu JinXia
Published: April 2023

The introduction of more stringent emission regulatory standards, such as China 6 and Euro 6, with test cycles that are more representative of real-world driving, from WLTP to RDE presents significant challenges to the emission development of internal combustion engine program. In the typical development process, the emission development requires complex work such as after-treatment development and calibration optimizations. In addition, it is late in the process, after the prototype vehicle that is more representative of the production status is ready. To address the situation outlined above, an Engine-in-the-Loop (EIL) testing methodology is developed at SAIC Motor, to front load part of the emission development work to the engine testbed early in the development stage, in the face of ever compressed vehicle program development time.

This methodology is to emulate vehicle operations on the engine testbed. Key techniques are developed to achieve this. Simulation models are developed to be used in the SAIC’s engine testbed environment, including vehicle model, road model, driver model, simplified transmission model. Engine dynamometer dynamic capabilities is enhanced by realizing high dynamic torque control. Residual bus simulations are created, to simulate missing CAN signal from the vehicle CAN bus on the engine test bed, so that real ECU could function properly. An integration platform is established, so that the signals and data from real-time simulation models are connected with test bed automation system through high speed dyno CAN. These key techniques ensure that engine operates normally on the test bed in a virtual vehicle testing environment.

This paper presents the detailed development of the methodology, the validation of the methodology with comparisons between vehicle RDE test cycle results and EIL testbed results. Effect of RDE route on the emissions is also investigated using EIL method.
Modeling of Transient Gasoline Engine Emissions using Data-Driven Modeling Techniques
Authors: Sundaram Ganesh , Gehra Tobias , Ulmen Jonas , Heubaum Mirjan , Görges Daniel , Guenthner Michael
Published: April 2023

In recent years, the automotive industry has shifted from purely combustion engine-driven vehicles towards hybridization due to the introduction of CO2 emission legislation. Hybrid powertrains also represent an important pillar and starting point in the journey towards zero-emission and full electrification. Fulfilling the most recent emission standards requires efficient control strategies for the engine, capable of real-time operation. Model accuracy is one of the main parameters which directly influence the performance of such control strategies. Specific methodologies developed in the past, such as physically- or phenomenologically-based approaches, have already facilitated the modeling of the combustion engine. Even though these models can accurately predict emissions in steady state conditions, their performance during transient engine operation is time-consuming and still not sufficiently reliable. The major contribution of the current work is to clarify and apply the recent advancements in data-driven modeling techniques, especially in time series forecasting with feedforward neural networks (FFNNs) and long short-term memory networks (LSTMs), to address the limitations mentioned above and to compare the different approaches.

The quantity and quality of data are significant challenges for data-driven modeling. This paper studies the modeling of gasoline engine emissions using FFNNs and LSTMs. The data quantity and quality requirements are studied based on a portable emission measurement system (PEMS), measuring at 1 Hz, and additional analyses on an engine test bench with a HiL setup, providing the possibility of increasing the measurement frequency with more sophisticated devices by a factor of five. Subsequently, the training and validation of the FFNNs and LSTMs are outlined, and finally, the model accuracy is discussed.
Simulation Based Visual Study of Particulate Deposition Characteristics in Millimeter-Scale Channels of a Diesel Particulate Filter
Authors: Duan Lishuang , TAN Piqiang , Chen Ying-jie , Lou Diming , Hu Zhiyuan
Published: April 2023

The diesel particulate filter (DPF) is an effective device for reducing particulate emissions from diesel engines, while its durability and reliability after long-term use are causes for concern. Usually, particulates are considered to be uniformly deposited in DPF channels to form a cake or end plug, however, recent studies have found that a “middle channel deposit” phenomenon of particulates can form a bridge near the middle of the DPF channel. This phenomenon has serious adverse effects on the durability and reliability of the DPF, including abnormally increased pressure drop and frequent regeneration. Since the width of the DPF channel is only about 1-2 millimeters, conventional methods cannot observe the particulate deposition process inside the DPF. In order to deeply understand the mechanism for the formation of the bridge phenomenon, this paper establishes a verified three-dimensional model of the DPF channel, including two 1/4 inlet channels and two 1/4 outlet channels, so as to observe the particulate deposition process. The effects of exhaust parameters (including mass flow, exhaust temperature, and particulate size) and structural parameters (including permeability, wall thickness, and cell density) on particulate deposition characteristics in the channels were investigated. It is found that the particulate deposition position is closer to inlet at small exhaust flow and low exhaust temperature conditions. Reducing the wall thickness and cell density can also increase the number of particulates deposited upstream and the middle of inlet channel. The results clarify the causes of “middle channel deposit” of particulates, which will help to understand the particulate deposition process in millimeter DPF channels, so as to provide ideas for the optimal design of DPF, as well as the improvement of durability and reliability.
Fresh and Aged Organic Aerosol Emissions from Renewable Diesel-Like Fuels HVO and RME in a Heavy-Duty Compression Ignition Engine
Authors: Novakovic Maja , Eriksson Axel , Gren Louise , Malmborg Vilhelm , Shamun Sam , Karjalainen Panu , Svenningsson Birgitta , Tuner Martin , Verhelst Sebastian , Pagels Joakim
Published: April 2023

A modern diesel engine is a reliable and efficient mean of producing power. A way to reduce harmful exhaust and greenhouse gas (GHG) emissions and secure the sources of energy is to develop technology for an efficient diesel engine operation independent of fossil fuels. Renewable diesel fuels are compatible with diesel engines without any major modifications. Rapeseed oil methyl esters (RME) and other fatty acid methyl esters (FAME) are commonly used in low level blends with diesel. Lately, hydrotreated vegetable oil (HVO) produced from vegetable oil and waste fat has found its way into the automotive market, being approved for use in diesel engines by several leading vehicle manufacturers, either in its pure form or in a mixture with the fossil diesel to improve the overall environmental footprint. There is a lack of data on how renewable fuels change the semi-volatile organic fraction of exhaust emissions. In order to characterize and explain the difference in exhaust emissions from fossil diesel, HVO and RME fuels, particulate matter (PM) emissions were sampled at two exhaust positions of an experimental single cylinder Scania D13 heavy-duty (HD) diesel engine: at the exhaust manifold, and after a diesel oxidation catalyst (DOC). Advanced analyzing techniques were used to characterize the composition of the organic PM. Special attention was paid to an operating point at 18% intake oxygen level with constant engine operating conditions where the emission level of nitrogen oxides (NOx) was low, and carbon monoxide (CO) and total hydrocarbon (THC) were relatively low. On-line aerosol mass spectrometry (AMS) suggests that the chemical composition of the organic aerosols (OAs) was similar for HVO and diesel. However, RME both reduced the OA emissions and changed the composition with evidence for fuel signatures in the mass spectra. When the emissions were aged in an oxidation flow reactor to simulate secondary organic aerosol (SOA) formation in the atmosphere, it was found that OA concentration strongly increased for all fuels. However, SOA formation was substantially lower for RME compared to the other fuels. The DOC strongly reduced primary organic emissions in both the gas (THC) and particle phase (OA) and only marginally affected OA composition. The DOC was also effective in reducing secondary organic aerosol formation upon atmospheric aging.
Design Analysis and Development of Aluminium Cylinder Block with Slip-Fit Cylinder Liners for High Performance New Generation Passenger Car Diesel Engine
Authors: KAWATKAR AMIT G. , Vellandi Vikraman , Dharan R Bharani , Loganathan S
Published: April 2023

The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. There is a high demand for passenger car segment vehicles with high torque delivery and fuel economy for a pleasant drivability experience. Also, to meet the more stringent emission requirements, automakers are trying very hard to reduce the overall vehicle gross weight. In lowering both fuel consumption and CO2 generation, serious efforts have been made to reduce the overall engine weight. An engine cylinder block is generally considered to be the heaviest part within a complete engine and block alone accounts for 3-4% of the total weight of the average vehicle, thus playing a key role in weight reduction consideration. Aluminum casting alloys as a substitute for the traditional cast iron can mean a reduction in engine block weight between 40 and 55% [9], even if the lower strength of aluminum compared to grey cast iron is considered. Thus, designers of aluminum engine blocks are constantly striving to design better and lighter blocks in order to improve and enhance the efficiency of automobile engines.

This work is a part of design and development of 2.2 L, 4-cylinder turbocharged intercooler (TCIC) diesel engine for a complete new monocoque vehicle platform, focused on automotive passenger car application with high operating in cylinder combustion pressures around 190 bar. The paper portrays the effective system approach essential for selecting aluminum as the choice of material, selection of alloy composition, casting process, heat treatment and key design criteria. The ongoing substitution of cast iron in engine blocks by aluminum casting alloys also requires the design and development of a new “tribological” system. Selection of cost-effective cylinder liner system and the drawbacks of this heterogeneous concept such as the lack of metallic bonding with the surrounding cast aluminum alloy and higher bore distortion are addressed during design and development. Statistical database, quality tools like design failure mode and effect analysis (DFMEA), design for manufacture and assembly (DFMA) etc., classical design methods, finite element analysis (FEA), advanced computer-aided engineering (CAE) and computational fluid dynamics (CFD) simulation tools have helped in materializing this concept into production. Experimental validation of the design is carried out as a part of design verification and validation. And results are elaborated to show the effectiveness of integrated approach used for the development program.
Numerical Study on High-Load Performance of a Two-Stage Boosted Poppet-Valved Two-stroke Diesel Engine
Authors: Fu Xue-Qing , Zhang Yan , Ding Zhanming , Zhuang Anbang , Zhu Wei , Hou Linlin , cheng Jianghua , Zhang Shuyong
Published: April 2023

Two-stroke cycle is one of the most effective methods to increase the torque and power output of a four-stroke engine due to the doubled firing frequency compared to four-stroke cycle at the same engine speed. As the two-stroke cycle lacks separate intake and exhaust strokes, the positive pressure difference between intake and exhaust ports is required to drive fresh charge into the cylinder, and is affected by intake port structures due to the different amounts of short-circuited fresh charge during scavenging process. To evaluate the effects of intake port structures on the high-load performance of a boosted poppet-valved two-stroke diesel engine, one-dimensional gas dynamic model and three-dimensional computational fluid dynamics model were established and used to predict the high-load performance of the boosted two-stroke diesel engine with top-entry intake ports, inclined side-entry intake ports, and side-entry intake ports, respectively. The results show that the engine with inclined side-entry intake ports has a much higher scavenging quality coefficient than the engine with other intake port structures. The maximum brake power of the 4.1 L four-cylinder two-stroke diesel engine equipped with a two-stage serial boosting system with a turbocharger and a downstream supercharger can reach 1.4 times that of a 5.1 L four-cylinder four-stroke diesel engine in the cases of top-entry and inclined side-entry intake ports, while that of the two-stroke engine with side-entry intake ports can only reach 1.2 times that of the four-stroke engine due to more power consumed by the supercharger resulted by large amount of short-circuited fresh charge. When the brake power of two-stroke engine is equal to 1.2 times that of the four-stroke engine, the intake pressure and mass flow rate of fresh charge are obviously decreased about 37.3% and 39.3% when intake port structure is changed from side-entry intake ports to inclined side-entry intake ports.
A Novel Model-Based Approach for Evaluating Multi-Speed Transmission Systems for BEVs
Authors: Skarlis Stavros , Molos Theodoros
Published: April 2023

State of the art battery electric vehicles (BEVs) become increasingly attractive, thanks to their top performance and high energy efficiency. Nevertheless, despite improvements in electric motors efficiency and motive batteries technology, there is still space for improving BEVs’ autonomy. Among others, use of a multi-speed, instead of a single-speed transmission system has the potential to optimize BEV’s energy consumption and driving range. In this respect, the scope of this work is to demonstrate a novel model-based approach for evaluating the potential of multi-speed gear box technology. For this purpose, advanced vehicle modeling was combined with statistical analysis tools and an optimization algorithm, with an aim to optimize gear ratios and the respective gear shifting strategy, ultimately maximizing BEV’s autonomy and performance. Respective results allow for an in-depth analysis of the multi-speed transmission system, already at early stages of a BEV development, which can eventually minimize battery electric powertrain system design time and cost.
Tooth Mesh Characterization of Spur Gear Pairs with Surface Pitting Damage
Authors: Thunuguntla Suhas Gupta , Hood Adrian , Cooley Christopher
Published: April 2023

A finite element/contact mechanics (FE/CM) method is used to determine the tooth contact forces, static transmission error, and tooth pair stiffnesses for spur gear pairs that have pitting damage. The pitting damage prevents portions of the tooth surface from carrying load, which results in meaningfully different contact pressure distribution on the gear teeth and deformations at the mesh. Pits of elliptical shape are investigated. Parametric analyses are used to investigate the effect of pit width (along the tooth face) and height (along the tooth profile) on the gear tooth mesh interface. Pitting damage increases static transmission error and decreases tooth pair stiffness. Tooth contact forces differ only in the portions of the mesh cycle when multiple pairs of teeth are in contact and share the transmitted load. Pitting damage does not change the loads when only a single pair of teeth are in contact. The duration of the mesh cycle where the static transmission error and tooth pair stiffnesses deviate from those for healthy teeth also increases with increasing damage area. Pitting damage originating at the pitch generally results in significant static transmission error and tooth pair stiffness variations from healthy when only a single pair of teeth are in contact. When the damage originates elsewhere on the tooth, large differences in these results occur in regions of the mesh cycle when multiple pairs of teeth carry the load. Accurate gear tooth contact analyses require more refined contact grids to accurately capture the steep contact pressure gradients near damage. The static transmission errors, mesh stiffnesses, and tooth contact forces determined in this work could be used to determine the damage-induced dynamic response from analytical gear models.
Power Loss Studies for Rolling Element Bearings Subject to Combined Radial and Axial Loading
Authors: Zhou SEN , Singh Avinash , Kahraman Ahmet , Hong Isaac , Vedera Kevin
Published: April 2023

The power loss of bearings is a significant factor in the overall efficiency in a drive unit system. Such bearings are subject to combined radial and axial loading needed to support the gear mesh forces. An experimental methodology has been developed to perform sets of power loss measurements on TRB, 4PCBB and DGBB. These measurements were performed under a variety of speed, load, temperature, and lubrication conditions. The loss behaviors of these types of the bearings are discussed, along with the tradeoff of different bearing arrangements for the fuel economy cycles. Several power loss models are employed to assess the accuracy of the estimations as compared to the experimental measurements. At low speed some models showed good correlations for TRB and DGBB, while at higher speed, they start deviating from the testing results. A higher fidelity model for estimating the losses at high speed, especially speed around 20krpm and beyond, needs to be developed. For 4PCBB, the models showed under prediction for the losses within the testing range.
Specialised Gear Rig for the Assessment of Loaded Transmission Error, Line of Action and Summarized Mesh Point
Authors: Leighton Michael , Surányi Marcell
Published: April 2023

Within gear pair development, the simulation of loaded transmission error, line of action and summarized mesh point are crucial information in design optimization as well as reliability, NVH and efficiency prediction. These properties and variables are difficult to evaluate and are usually only assessed through proxy-variables such as unloaded transmission error or contact pattern assessment. Alternatively, large design loops can be generated when prototypes are produced to directly assess the results of reliability, NVH and efficiency and simulation models updated to the results, but not directly calibrated.

This work will showcase an advanced test facility with the unique capabilities to evaluate all gear contact types (including hypoid, beveloid, cylindrical and spiral) under loaded conditions while assessing position and force data that can be used to validate simulation models directly and enhance design development.

Results will be shown for the assessment of hypoid gear fatigue life while also showing the effect of manufacturing tolerances on performance and the evolution of these critical variables throughout the life as they vary with run-in and gradual flank wear.