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The trend towards renewable energy sources will continue under the pre-amble of greenhouse gas (GHG) emission reduction targets. The main question is how to harvest and store renewable energy properly. The challenge of intermittency of the renewable energy resources make the supply less predictable compared to the traditional energy sources. Chemical energy carriers like hydrogen and synthetic fuels (e-Fuels) seem to be at least a part of the solution for storing renewable energy. The usage of e-Fuels in the existing ICE-powered vehicle fleet has a big lever arm to reduce the GHG emissions of the transport sector in the short- and medium term. The paper covers the whole well-to-wheel (WtW) pathway by discussing the e-Fuel production from renewable sources, the storage and the usage in the vehicle. It will be summarized by scenarios on the impact of e-Fuel to the WtW CO2 fleet emissions.

E-mobility is a game changer for the automotive domain. It promises significant reduction in terms of complexity and in terms of local emissions. With falling prices and recent technological advances, the second generation of electric vehicles (EVs) that is now in production makes electromobility an affordable and viable option for more and more transport mission (people, freight). Still, major challenges for large scale deployment remain. They include higher maturity with respect to performance (e.g., range, interaction with the grid), development efficiency (e.g., time-to-market), or production costs. Additionally, an important market transformation currently occurs with the co-development of automated driving functions, connectivity, mobility-as-a-service. New opportunities arise to customize road transportation systems toward application-driven, user-centric smart mobility solutions.

The influence of big-end bore fretting on connecting rod fatigue fracture is investigated. A finite element model, including rod-bearing contact interaction, is developed to simulate a fatigue test rig where the connecting rod is subjected to an alternating uniaxial load. Comparison of the model results with a rod fracture from the fatigue rig shows good correlation between the fracture location and the peak ‘Ruiz’ criterion, rather than the peak tensile stress location, indicating the potential of fretting to initiate a fatigue fracture and the usefulness of the ‘Ruiz’ criterion as a measure of location and severity. The model is extended to simulate a full engine cycle using pressure loads from a bearing EHL analysis. A fretting map and a ‘Ruiz’ criterion map are developed for the full engine cycle, giving an indication of a safe ‘Ruiz’ level from an existing engine which has been in service for more than 5 years.

Increasingly stringent greenhouse gas and emission limits demand for powertrain electrification throughout all vehicle applications. Beside fully electric powertrains different configurations of hybrid powertrains will have an important role in upcoming and future vehicle generations. As already discussed in previous papers, the requirements on the combustion engine in hybrid powertrains are different to those in a conventional powertrain solution, heading for brake thermal efficiency targets of 45% and above within the product lifecycle for conventional fuels. Focus on product cost and production and assembly facility investment drives reuse of technology packages within modular powertrain technology platforms, with different combinations of internal combustion engines (ICE), transmissions, and e-drive-layouts. The goal of zero carbon operation requires compatibility of ICE for sustainable fuels.

The performance characteristics of a commercial lean-NOX trap catalyst were evaluated between 200 and 500°C, using H2, CO, and a mixture of both H2 and CO as reductants before and after different high-temperature aging steps, from 600 to 750°C. Tests included NOX reduction efficiency during cycling, NOX storage capacity (NSC), oxygen storage capacity (OSC), and water-gas-shift (WGS) and NO oxidation reaction extents. The WGS reaction extent at 200 and 300°C was negatively affected by thermal degradation, but at 400 and 500°C no significant change was observed. Changes in the extent of NO oxidation did not show a consistent trend as a function of thermal degradation. The total NSC was tested at 200, 350 and 500°C. Little change was observed at 500°C with thermal degradation but a steady decrease was observed at 350°C as the thermal degradation temperature was increased.

Rattle noise produced in the vehicle interior due to broadband excitation by road irregularities is a major concern with respect to driving comfort, and therefore has become one of the most important topics of acoustic development in recent years. A quantification i.e. measurement of this rattle noise is of fundamental importance for systematic development work and production control. Common noise level measurements (dB, dBA, etc. ) do not represent the rattle character in the vehicle interior as revealed during initial investigations. To overcome this problem and to substitute the subjective assessment with a combination of measurable parameters, the psychoacoustic software AVL-EAR was applied to create an Interior Rattle Quality Index. Based on more than 40 different vehicles that have been subjectively assessed by approximately 70 test persons, the index was generated by means of multiple pair comparisons and statistics on measurement data.

In order to achieve future CO2 targets - in particular under real driving conditions - different powertrain technologies will have to be introduced. Beside the increasing electrification of the powertrain, it will be essential to utilize the full potential of the internal combustion engine. In addition to further optimization of the combustion processes and the reduction of mechanical losses in the thermal- and energetic systems, the introduction of Variable Compression Ratio (VCR) is probably the measure with the highest potential for fuel economy improvement. VCR systems are expected to be introduced to a considerable number of next generation turbocharged Spark Ignited (SI) engines in certain vehicle classes. The basic principle of the AVL VCR system described in this paper is a 2-stage variation of the conrod length and thus the Compression Ratio (CR).

Sulfur poisoning from engine fuel and lube is one of the most recognizable degradation mechanisms of a NOx adsorber catalyst system for diesel emission reduction. Even with the availability of 15 ppm sulfur diesel fuel, NOx adsorber will be deactivated without an effective sulfur management. Two general pathways are currently being explored for sulfur management: (1) the use of a disposable SOx trap that can be replaced or rejuvenated offline periodically, and (2) the use of diesel fuel injection in the exhaust and high temperature de-sulfation approach to remove the sulfur poisons to recover the NOx trapping efficiency. The major concern of the de-sulfation process is the many prolonged high temperature rich cycles that catalyst will encounter during its useful life. It is shown that NOx adsorber catalyst suffers some loss of its trapping capacity upon high temperature lean-rich exposure.

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.

Plug flow reactors, simulating engine exhaust gas, are widely used in emissions control research to gain insight into the reaction mechanisms and engineering aspects that controls activity, selectivity, and durability of catalyst components. The choice of relevant hydrocarbon (HC) species is one of the most challenging factor in such laboratory studies, given the variety of compositions that can be encountered in different application scenarios. Furthermore, this challenge is amplified by the experimental difficulties related to introducing heavier and multi-component HCs and analyzing the reaction products.

Advanced flow-reactor capabilities created at Cummins were applied to the study of the diesel particulate matter (soot) oxidation process. This approach complemented the on-engine studies with a number of important features, including accurate control of gas composition and soot layer temperature. Using the developed methodology for quantitative soot oxidation studies in a broad range of temperatures (200-700°C), an initial set of experiments was performed to compare the behavior of the real and model soot samples under the identical conditions (10%vol. of O2, 0-15%vol. of H2O). It was found that presence of H2O vapor synergistically enhances the rate of oxidation by O2 of the diesel soot sample. However, the behavior of the model soot sample (carbon black) was virtually not affected by H2O. Kinetic analysis of the obtained results revealed an unusual type of behavior, with the activation energy of soot oxidation increasing in the course of the experiment.

A growing development of hybrid or fully electrical drives increases the demand for an accurate prediction of noise and vibration characteristics of electric and electronic components. This paper describes the numerical and experimental investigation of noise emissions from power electronics, as one of the new important noise sources in electric vehicles. The noise emitted from the printed circuit board (PCB) equipped with multi-layer ceramic capacitors (MLCC) is measured and used for the calibration and validation of numerical model. Material properties are tuned using results from experimental modal analysis, with special attention to the orthotropic characteristic of the PCB glass-reinforced epoxy laminate sheet (FR-4). Electroacoustic excitation is pre-calculated using an extension of schematic-based EMC simulation and applied to the structural model. Structural vibrations are calculated with a commercial FEM solver with the modal frequency response analysis.

Growing development of hybrid and fully electrical drives increases demand for accurate prediction of noise and vibration characteristic of electric and electronic components. This paper describes the numerical and experimental investigation of noise emission from PMSM electric machine as a one of the most important noise sources in electric vehicles. Structural and air borne noise is measured on e-machine test rig and used for calibration and validation of the numerical model. The electro-magnetic field in PMSM is simulated using finite volume method. Electro-magnetic forces are applied as excitation to the 3D FE model of e-machine, mounded on test frame. Material properties are tuned using results from experimental modal analysis including identification of orthotropic characteristic of stator laminated core, assembled together with coil and end winding. Structural vibrations are calculated by modal frequency response analysis and applied as excitation in air borne noise simulation.

The paper is devoted to the coupled 1D-3D modeling technology of injector flow and cavitation in diesel injections systems. The technology is based on the 1D simulation of the injector with the AVL software BOOST-HYDSIM and 3D modeling of the nozzle flow with AVL FIRE. The nozzle mesh with spray holes and certain part of the nozzle chamber is created with the FIRE preprocessor. The border between the 1D and 3D simulation regions can be chosen inside the nozzle chamber at any position along the needle shaft. Actual coupling version of both software tools considers only one-dimensional (longitudinal) needle motion. Forthcoming version already includes the two-dimensional motion of the needle. Furthermore, special models for the needle tip contact with the nozzle seat and needle guide contact with the nozzle wall are developed in HYDSIM. The co-simulation technology is applied for different common rail injectors in several projects.

An operational challenge associated with SCR catalysts is the NH3 slip control, particularly for commercial small pore Cu-zeolite formulations as a consequence of their significant ammonia storage capacity. The desorption of NH3 during increasing temperature transients is one example of this challenge. Ammonia slipping from SCR catalyst typically passes through a platinum based ammonia oxidation catalyst (AMOx), leading to the formation of the undesired byproducts NOx and N2O. We have discovered a distinctive characteristic, an overlapping NH3 desorption and oxidation, in a state-of-the-art Cu-zeolite SCR catalyst that can minimize NH3 slip during temperature transients encountered in real-world operation of a vehicle.

Mitigation of ammonia slip from SCR system is critical to meeting the evolving NH₃ emission standards, while achieving maximum NOx conversion efficiency. Ammonia slip catalysts (ASC) are expected to balance high activity, required to oxidize ammonia across a broad range of operating conditions, with high selectivity of converting NH₃ to N₂, thus avoiding such undesirable byproducts as NOx or N₂O. In this work, new insights into the behavior of an advanced ammonia slip catalyst have been developed by using accelerated progressive catalyst aging as a tool for catalyst property interrogation. The overall behavior was deconstructed to several underlying functions, and referenced to an active but non-selective NH₃ oxidation function of a diesel oxidation catalyst (DOC) and to the highly selective but minimally active NH₃ oxidation function of an SCR catalyst.

Cooled EGR continues to be a key technology to meet emission regulations, with EGR coolers performing a critical role in the EGR system. Designing EGR coolers that reliably manage thermal loads is a challenge with thermal fatigue being a top concern. The ability to estimate EGR cooler thermal fatigue life early in the product design and validation cycle allows for robust designs that meet engine component reliability requirements and customer expectations. This paper describes a process to create an EGR cooler thermal fatigue life model. Components which make up the EGR cooler have differing thermal responses, consequently conjugate transient CFD must be used to accurately model metal temperatures during heating and cooling cycles. Those metal temperatures are then imported into FEA software for structural analysis. Results from both the CFD and FEA are then used in a simplified numerical model to estimate the virtual strain of the EGR cooler.

Cummins has recently launched next-generation aftertreatment technology, the Single ModuleTM aftertreatment system, for medium-duty and heavy-duty engines used in on-highway and off-highway applications. Besides meeting EPA 2010+ and Euro VI regulations, the Single ModuleTM aftertreatment system offers 60% volume and 40% weight reductions compared to current aftertreatment systems. In this work, we present model-based approaches that were systematically adopted in the design and development of the Cummins Single ModuleTM aftertreatment system. Particularly, a variety of analytical and experimental component-level and system-level validation tools have been used to optimize DOC, DPF, SCR/ASC, as well as the DEF decomposition device.

The present paper deals with the application of the LES approach to in-cylinder flow modeling. The main target is to study cycle-to-cycle variability (CCV) using 3D-CFD simulation. The engine model is based on a spark-ignited single-cylinder research engine. The results presented in this paper cover the motored regime aiming at analysis of the cycle-resolved local flow properties at the spark plug close to firing top dead center. The results presented in this paper suggest that the LES approach adopted in the present study is working well and that it predicts CCV and that the qualitative trends are in-line with established knowledge of internal combustion engine (ICE) in-cylinder flow. The results are evaluated from a statistical point of view based on calculations of many consecutive cycles (at least 10).

Real-world operation of diesel oxidation catalysts (DOCs), used in a variety of aftertreatment systems, subjects these catalysts to a large number of permanent and temporary deactivation mechanisms. These include thermal damage, induced by generating exotherm on the catalyst; exposure to various inorganic species contained in engine fluids; and the effects of soot and hydrocarbons, which can mask the catalyst in certain operating modes. While some of these deactivation mechanisms can be accurately simulated in the lab, others are specific to particular engine operation regimes. In this work, a set of DOCs, removed from prolonged service in the field, has been subjected to a detailed laboratory study. Samples obtained from various locations in these catalysts were used to characterize the extent and distribution of deactivation.