The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Pischinger, Stefan
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Analysis of Drivability Influence on Tailpipe Emissions in Early Stages of a Vehicle Development Program by Means of Engine-in-the-Loop Test Benches

FEV Europe GmbH-Stefan Tegelkamp, Michael Görgen, Martin Nijs, Johannes Scharf
RWTH Aachen University-Christian Heusch, Daniel Guse, Frank Dorscheidt, Johannes Claßen, Timm Fahrbach, Stefan Pischinger
  • Technical Paper
  • 2020-01-0373
To be published on 2020-04-14 by SAE International in United States
Due to increasing environmental awareness, standards for pollutant and CO2 emissions are getting stricter in most markets around the world. In important markets such as Europe, also the emissions during real road driving, so called “Real Driving Emissions” (RDE), are now part of the type approval process for passenger cars. In addition to the proceeding hybridization and electrification of vehicles, the complexity and degrees of freedom of conventional powertrains with internal combustion engines (ICE) are also continuing to increase in order to comply with stricter exhaust emission standards. Besides the different requirements placed on vehicle emissions, the drivability capabilities of passenger vehicles desired by customers, are essentially important and vary between markets. As the interactions between different hardware and software parts of the powertrain strongly influence the drivability characteristics of a vehicle, a high degree of maturity of test vehicles is required to execute drivability calibration tasks with a reliable evidence. Hence, these calibration and evaluation tasks are generally conducted in late phases of the vehicle development process where the engines base calibration is already…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Relevance of Exhaust Aftertreatment System Degradation for EU7 Gasoline Engine Applications

FEV Europe GmbH-Michael Görgen, Jim Cox, Martin Nijs, Johannes Scharf
RWTH Aachen University-Stefan Sterlepper, Johannes Claßen, Stefan Pischinger
  • Technical Paper
  • 2020-01-0382
To be published on 2020-04-14 by SAE International in United States
Exhaust aftertreatment systems must function sufficiently over the full useful life of a vehicle. In Europe this is currently defined as 160.000 km. With the introduction of Euro 7 it is expected that the required mileage will be extended to 240.000 km. This will then be consistent with the US legislation.In order to quantify the emission impact of exhaust system degradation, an Euro 7 exhaust aftertreatment system is aged by different accelerated approaches: application of the Standard Bench Cycle, the ZDAKW cycle, a novel ash loading method and borderline aging. The results depict the impact of oil ash on the oxygen storage capacity. For tailpipe emissions, the maximum peak temperatures are the dominant aging factor. The cold start performance is effected by both, thermal degradation and ash accumulation.An evaluation of this emission increase requires appropriate benchmarks. For this purpose, an analysis of the emission impacts of ambient temperatures, driving modes and particulate filter regenerations follows. The comparison shows the severe impact of very low ambient conditions. Considering the high statistical relevance of catalyst degradation however,…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Objectified Evaluation and Classification of Passenger Vehicles Longitudinal Drivability Capabilities in Automated Load Change Drive Maneuvers at Engine-in-the-Loop Test Benches

FEV Europe GmbH-Stefan Tegelkamp, Martin Nijs, Johannes Scharf
RWTH Aachen University-Daniel Guse, Christian Heusch, Serge Klein, Timm Fahrbach, Jakob Andert, Stefan Pischinger
  • Technical Paper
  • 2020-01-0245
To be published on 2020-04-14 by SAE International in United States
The growing number of passenger car variants and derivatives in all global markets, their high order of software differentiability caused by regionally different legislative regulations, as well as pronounced market-specific customer expectations require a continuous optimization of the entire vehicle development process. Additionally, the continued increasingly stringent emission standards lead to considerable increases in powertrain hardware and control complexity. Also, efforts to achieve global market and brand specific multistep adjustable drivability characteristics as unique selling proposition, rapidly increase the scope for calibration and testing tasks during the development of the powertrain control units. The resulting extent of interdependencies between the drivability calibration and other development and calibration tasks require frontloading of development tasks. Usually, drivability calibration takes place towards the end of the vehicle development program as soon as a sufficient level of product maturity is achieved. Hence, for streamlining the entire development process, various powertrain engineering tasks have to be shifted from the overall vehicle level to component conception phases. In this context, highly dynamic “Hardware-in-the-Loop” (HiL) component test benches are the means of…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Dynamic oil pressure in connecting rod bearings and their influence on innovative cranktrain technologies

Institute for Combustion Engines VKA, RWTH Aachen University-Denis Pendovski, Stefan Pischinger
  • Technical Paper
  • 2019-01-2333
Published 2019-12-19 by SAE International in United States
In order to lower friction losses and hence ensure low fuel consumption of internal combustion engines, borderline design of hydrodynamic cranktrain bearings is often unavoidable. To realize this without the risk of failures, detailed modelling of hydrodynamic effects is gaining more and more relevance. In this publication, an approach using flow simulation to couple hydrodynamic bearings with each other, will be introduced. This allows the state variables of the fluid in the supply bore of the crankshaft to be calculated transiently. One important aspect of this concerns the solubility of gas in oil. This paper demonstrates that the gas fractions in the supply bore of the crankshaft influence the pressures at the hydrodynamic bearings. Additionally, simulation results will be shown and also validated with measurement data. Beside the application for conventional cranktrains, the developed methodology can also be applied to investigate lubrication systems, which include innovative technologies such as hydraulic, length adjustable connecting rods employed for variable compression ratio (VCR connecting rod).
This content contains downloadable datasets
Annotation ability available

Evaluation of the Potential of Direct Water Injection in HCCI Combustion

Dept. of Mechanical Engineering, University of Alberta, Cana-David Gordon
Institute for Combustion Engines, RWTH Aachen University, Ge-Christian Wouters, Tamara Ottenwälder, Bastian Lehrheuer, Stefan Pischinger
  • Technical Paper
  • 2019-01-2165
Published 2019-12-19 by SAE International in United States
Homogeneous charge compression ignition (HCCI) is a part load, low-temperature combustion process which operates at lean mixtures and produces ultra-low NOX emissions. As opposed to SI engines that use a spark to control combustion timing, HCCI combustion is enabled by compression induced autoignition which is characterized by rapid global and spatial combustion yielding fuel efficiency benefits. This process is highly dependent on the in-cylinder state, including pressure, temperature and trapped mass. The absence of a direct combustion control proves to be a major challenge and results in unstable engine operation especially at the limits of the narrow operation range. In recent studies, direct water injection is used in HCCI combustion to stabilize combustion and increase the operation range. This paper outlines the thermodynamic influence and evaluation of the potential of water injection for HCCI combustion. Investigations were performed on two single cylinder research engines using different fuels to investigate the effect of direct water injection on HCCI combustion. In this work, the required energy to achieve autoignition is obtained using internal exhaust gas recirculation which…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Optical Spray Investigations on OME3-5 in a Constant Volume High Pressure Chamber

FEV Europe GmbH-Sandra Glueck, Markus Schoenen
RWTH Aachen Univ.-Christian Honecker, Marcel Neumann, Stefan Pischinger
Published 2019-10-07 by SAE International in United States
Oxygenated fuels such as polyoxymethylene dimethyl ethers (OME) offer a chance to significantly decrease emissions while switching to renewable fuels. However, compared to conventional diesel fuel, they have lower heating values and different evaporation behaviors which lead to differences in spray, mixture formation as well as ignition delay. In order to determine the mixture formation characteristics and the combustion behavior of neat OME3-5, optical investigations have been carried out in a high-pressure-chamber using shadowgraphy, mie-scatterlight and OH-radiation recordings. Liquid penetration length, gaseous penetration length, lift off length, spray cone angle and ignition delay have been determined and compared to those measured with diesel-fuel over a variety of pressures, temperatures, rail pressures and injection durations. Liquid penetration lengths for OME3-5-sprays were found to be shorter than that of diesel-fuel analogues, while lift-off-lengths were generally observed to be longer for OME3-5, resulting in longer gaseous mixing lengths. As the cetane numbers suggested, ignition delay was found to be shorter for OME3-5. Spray cone angles were reduced at low temperature and wider at high temperature, while gaseous penetration…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Analysis of the Emission Conversion Performance of Gasoline Particulate Filters Over Lifetime

Corning GmbH-Dominik Rose, Thorsten Boger
FEV Europe GmbH-Christof Schernus, Michael Görgen, Jim Cox, Martin Nijs, Johannes Scharf
Published 2019-09-09 by SAE International in United States
Gasoline particulate filters (GPF) recently entered the market, and are already regarded a state-of-the-art solution for gasoline exhaust aftertreatment systems to enable EU6d-TEMP fulfilment and beyond. Especially for coated GPF applications, the prognosis of the emission conversion performance over lifetime poses an ambitious challenge, which significantly influences future catalyst diagnosis calibrations. The paper presents key-findings for the different GPF application variants. In the first part, experimental GPF ash loading results are presented. Ash accumulates as thin wall layers and short plugs, but does not penetrate into the wall. However, it suppresses deep bed filtration of soot, initially decreasing the soot-loaded backpressure. For the emission calibration, the non-linear backpressure development complicates the soot load monitoring, eventually leading to compromises between high safety against soot overloading and a low number of active regenerations. In the second part, a relevant share of ash deposits inside three-way catalysts (TWC) is depicted. In an experiment, the oxygen storage capacity (OSC) of a three-way catalyst was significantly lowered by ash, while a coated GPF showed little effects. A subsequent OSC regeneration…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Efficient Test Bench Operation with Early Damage Detection Systems

BEA Testing GmbH-Matthias Pouch, Carsten Küpper
RWTH Aachen University-Thomas Laible, Stefan Pischinger
Published 2019-09-09 by SAE International in United States
The efficient operation of powertrain test benches in research and development is strongly influenced by the state of “health” of the functional test object. Hence, the use of Early Damage Detection Systems (EDDS) with Unit Under Test (UUT) monitoring is becoming increasingly popular. An EDDS should primarily avoid total loss of the test object and ensure that damaged parts are not completely destroyed, and can still be inspected. Therefore, any abnormality from the standard test object behavior, such as an exceeding of predefined limits, must be recognized at an early testing time, and must lead to a shutdown of the test bench operation. With sensors mounted on the test object, it is possible to isolate the damage cause in the event of its detection. Advanced EDDS configurations also optimize the predefined limits by learning new shutdown values according to the test object behavior within a very short time.In this paper, the expectations on an EDDS and its general structure are presented and discussed. The advantages and disadvantages in test bench operation are analyzed and compared…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

On the Measurement and Simulation of Flow-Acoustic Sound Propagation in Turbochargers

SAE International Journal of Advances and Current Practices in Mobility

FEV Europe GmbH-Ralf Stienen
Institute for Combustion Engines, RWTH Aachen University-Hendrik Ruppert, Felix Falke, Stefan Pischinger, Marco Günther
  • Journal Article
  • 2019-01-1488
Published 2019-06-05 by SAE International in United States
Most of today’s internal combustion engines are turbocharged by combined radial compressors and turbines for downsizing. This mostly leads to reduced orifice noise of both intake and exhaust systems, but the detailed damping mechanisms remain yet unknown. Intake and exhaust systems are developed with 1D-CFD simulations, but validated acoustic sub-models for turbochargers are not yet available. Therefore the aim of this publication is studying the turbocharger’s silencing capabilities and subsequently develop new acoustic turbocharger models.The acoustic properties of the turbocharger can be well described by transmission loss. In addition to thermodynamic variations, parameter variations with wastegate and VTG systems were also performed. A total of four turbochargers of very different sizes were investigated. Low frequency attenuation is dominated by impedance discontinuities, increasing considerably with mass flow and pressure ratio. High frequency transmission loss is generated by destructive interferences in the stator, which depend on the stator mass flow distribution and the turbocharger size.A new generic turbocharger model was developed to model both low frequency impedance discontinuities and high-frequency interferences by combining a generic geometric housing…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Separation, Allocation and Psychoacoustic Evaluation of Vehicle Interior Noise

Otto von Guericke University Magdeburg-Florian Doleschal, Jesko Verhey
RWTH Aachen University-Christian Schumann, Stefan Pischinger
Published 2019-06-05 by SAE International in United States
Besides optical and haptic criteria, the interior noise especially influences the quality impression of a vehicle. Separately audible disturbing noises are usually perceived as inadequate product quality. As a result, the reduction of disturbing noise components is a key factor for the overall product quality. Since the acoustic optimization is a complex and time consuming process, the need for an analysis tool which identifies automatically disturbing engine noise components within the vehicle interior noise is high. For this reason, a novel analysis tool has been developed which extracts tonal and impulsive engine noise components from the overall engine noise, and evaluates the annoyance of each noticeable engine component automatically. In addition, each disturbing noise is allocated to the emitting engine component. It is then possible to listen to each engine component noise individually and synthesize a target noise by superimposing manually weighted component noises. The noise separation into noise fragments is performed by means of the non-negative matrix factorization and image processing tools. These are then clustered according to their time correlation or other similarity-determining…
This content contains downloadable datasets
Annotation ability available