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

Combustion and combustion processes
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

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

Simulation of Driving Cycles by Means of a Co-Simulation Framework for the Prediction of IC Engine Tailpipe Emissions

Exothermia SA-Vasileios Tziolas, Nikolaos Zingopis
Politecnico di Milano-Gianluca Montenegro, Angelo Onorati, Gianluca D'Errico, Tarcisio Cerri, Andrea Marinoni
  • Technical Paper
  • 2020-37-0011
To be published on 2020-06-23 by SAE International in United States
The current European legislation concerning pollutant emissions from IC engine vehicles is very stringent and demanding. In addition, the CO2 fleet emission must obey to a significant reduction path during the next decade, to cope with the prescribed targets recently agreed. The prediction of pollutant emissions from IC engines has been a challenge since the introduction of the emission regulation legislation. During the last decade, along with the more tightening limits and increased public concern about air quality, the capability of simulating different operating conditions and driving cycles with an acceptable computational effort has become a key feature for modern simulation codes. The role of 1D thermo-fluid dynamic simulation models is extremely important to achieve this task, in order to investigate the performances of the next generation of IC engines working over a wide range of operating conditions, under steady-state and transient conditions. This work is based on the idea of integrating two different 1D simulation tools in a co-simulation environment, realizing a strict numerical coupling between the two codes. The main goal is to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The Virtual Engine Development for Enhancing the Compression Ratio of DISI-Engines by Means of Water Injection and Variable Valve Timing

FKFS-Antonino Vacca, Francesco Cupo, Marco Chiodi, Michael Bargende
Ford Werke GmbH-Oliver Berkemeier, Maziar Khosravi
  • Technical Paper
  • 2020-37-0010
To be published on 2020-06-23 by SAE International in United States
With the aim of significantly reducing emissions, while keeping CO2 production under control, gasoline engines are faced with a new challenge to survive the constraints imposed by the RDE cycles. Current downsized engines are developed with the most recent techniques for increasing efficiency, such as high direct injection pressure, selective valve actuation, variable turbine geometry, and innovative thermal management system. The factor limiting their further step towards enhanced efficiency is the onset of abnormal combustion process. Therefore the challenge for the further boost of modern engine efficiency is the improvement of the combustion process. Different combustion technics such as HCCI and the employment of pre-chamber have been investigated, but the possibility of effectively use them in a wide range of the engine map, by fulfilling at the same time the needing of fast load control are still limiting their dissemination. For these reasons the technologies for improving the characteristics of a standard combustion process are still deeply investigated. Among these water injection in combination with either early or late intake valve closing offers the possibility…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Prechamber on Exhaust Emission and Efficiency of a SI Small Engine Fuelled with Gaseous and Liquid Fuels

Istituto Motori CNR-Paolo Sementa
  • Technical Paper
  • 2020-37-0035
To be published on 2020-06-23 by SAE International in United States
The aim of the study was the optimization of the gasoline combustion process by means of a passive/active prechamber. The improvement of the engine efficiency in lean-burn operation condition is an opportunity to give further use of Spark Ignition (SI) engine. A commercial small Spark Ignition (SI) engine was modified with a proper designed prechamber fuelled with methane. Engine performance in terms of indicated Mean effective pressure, heat release rate and fuel Consumption were evaluated as well as gaseous emissions. Particulate Mass, Number and Size Distributions were measured. Several engine operative conditions were investigated at full load varying the engine speeds for stoichiometric and lean conditions and with different prechamber types. The results were compared with those obtained with the engine equipped with the standard spark plug. The results indicated that both performance and emissions were strongly influenced by the prechamber.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Fuel Consumption and Emission Reduction for Hybrid Electric Vehicles with electrically heated Catalyst

TU Dresden-Frank Atzler
TU Muenchen-Georg Wachtmeister
  • Technical Paper
  • 2020-37-0017
To be published on 2020-06-23 by SAE International in United States
Hybridization is a promising way to further reduce the CO2 emissions of passenger vehicles. However, high engine efficiencies and the reduction of engine load, due to torque assist by an electric motor, cause a decrease of exhaust gas temperature levels. This leads to an increased time to light-off of the catalysts resulting in an overall lower efficiency of the exhaust aftertreatment system. Especially in low load driving conditions, at cold ambient temperatures and on short distance drives, the tailpipe pollutant emissions are severely impacted by these low efficiency levels. To ensure lowest emissions at all driving conditions, catalyst heating methods must be used. In conventional vehicles internal combustion engine measures, e.g. late combustion can be applied. A hybrid system with an electrically heated catalyst enables further methods such as the increase of engine load, the so-called load point shifting by the electric motor or using the energy from the battery for electric catalyst heating. Since these methods result either directly or indirectly in additional fuel consumption there is a conflict of objectives between a fast…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Simplified Cost-effective Aftertreatment System for Electrified Diesel Applications

Exothermia SA-Dimitrios Karamitros, Christos Avgerinos, Stavros Skarlis, Grigorios Koltsakis
GM Global Propulsion System-Giuseppe Previtero, Fransesco Bechis
  • Technical Paper
  • 2020-37-0023
To be published on 2020-06-23 by SAE International in United States
The Diesel powertrain remains an important CO2 reduction technology in specific market segments due to its inherent thermodynamic combustion efficiency advantages. Diesel powertrain hybridization can bring further potential for CO2 emissions reduction. However, the associated reduction in the exhaust gas temperature may negatively impact the performance of the exhaust aftertreatment (EAT) system and challenge the abatement of other emissions, especially NOx. Considering that active urea-SCR systems may be required to ensure compliance with the legislative limits, the total cost of the hybrid Diesel powertrain is expected to increase even more, therefore making it less commercially attractive. We present a model-based analysis of a 48V Diesel mild hybrid electric vehicle (MHEV) which is combined with an exhaust aftertreatment (EAT) system using Lean-NOx trap (LNT) technology. The overall de-NOx performance is further enhanced with the addition of passive SCR catalysts to benefit from the on-board ammonia formation during rich combustion events. Since the modeling framework is fully physico-chemically informed, it allows the investigation of various topologies, catalyst geometrical and chemical properties. Moreover, the model includes a simplified…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A CFD Model of Supercritical Water Injection for ICEs as Energy Recovery System

University of Basilicata-Antonio Cantiani, Annarita Viggiano, Vinicio Magi
  • Technical Paper
  • 2020-37-0001
To be published on 2020-06-23 by SAE International in United States
Supercritical water injection for ICEs may be a valid option to recover engine wall heat transfer and energy from exhaust gases, with benefits in terms of efficiency and performances. Water is recovered from exhaust gases and is brought up to supercritical conditions by employing the waste heat during engine operations. A preliminary study of this energy recovery approach has already been performed in an authors’ previous work, by employing a port fuel injection (PFI) internal combustion engine quasi-dimensional model, which has been validated against experimental data, returning satisfactory results in terms of overall efficiency gain. In this work, in order to obtain a more reliable and accurate evaluation of the achievable energy recovery with supercritical water injection, a multidimensional CFD model of the engine has been set and validated. As regards the engine geometry, a simplified axial symmetric engine has been used, in order to reduce the computational time and storage. The combustion has been modelled with an ECFM model using an 88-species and 349-reactions chemical kinetics mechanism, in order to evaluate the pollutant emissions…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental Study of Additive-Manufacturing-Enabled Innovative Diesel Combustion Bowl Features for Achieving Ultra-low Emissions and High Efficiency

GM Global Propulsion Systems-Giacomo Belgiorno, Andrea Boscolo, Gennaro Dileo, Fabio Numidi, Francesco Concetto Pesce, Alberto Vassallo
Istituto Motori CNR-Roberto Ianniello, Carlo Beatrice, Gabriele Di Blasio
  • Technical Paper
  • 2020-37-0003
To be published on 2020-06-23 by SAE International in United States
In recent years the research on Diesel thermodynamics has been increasingly shifting from performance and refinement to ultra-low emissions and efficiency. In fact, the last two attributes are key for the powertrain competitiveness in the automotive electrified future, especially in European market where 95gCO2/km fleet average and Euro6d RDE Step2 are phasing in at the same time. The present paper describes some of the most innovative research that GM and Istituto Motori Napoli are performing in the field, exploring how the steel additive manufacturing can be used to create innovative combustion bowl features that optimize the combustion process to a level that was not compatible with standard manufacturing technologies. In particular, an innovative highly-reentrant sharp-stepped profile featuring radial-lips has been studied on a 0.5l single-cylinder engine, coupled to a state of art 2500bar fast-acting fuel injection system, with the objective to demonstrate the full potential of optimized fuel stratification and spray separation enabled by the radial mixing zone concept. The results confirm that excellent reduction of engine-out emissions vs a Euro6-b design could be achieved…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Numerical Investigation on VVA Influence on the Combustion Phase for Premixed Combustion Engine Under Partial Load Conditions

DMMM - Politecnico di Bari-Sergio Camporeale
DMMM - Politecnico di Bari, GNFM INDAM-Francesco Fornarelli
  • Technical Paper
  • 2020-37-0005
To be published on 2020-06-23 by SAE International in United States
Nowadays, the vehicle hybridization and the use of more clean fuel in heavy-duty applications brings to a new beginning in the use of spark ignition engine. In standard intake system, the pre-mixed fuel air mixture is controlled by the injection of fuel after the throttle valve. Then, intake system, consisting in intake duct, valve number and geometry and cylinder head shape influence the characteristics of the intake flow within the cylinder up to the ignition of the combustion by the spark plug. The technology advancement in fluid-power and electrical actuation gives the opportunity to decouple the intake and exhaust valve actuation with respect to the standard cam shaft distribution. The Variable Valve Actuation (VVA) concepts is not new, but its application is now affordable and flexible enough to be applied in partial load conditions. Here, by means of three-dimensional numerical simulations the intake and combustion process is studied with a finite volume approach to solve the mass, momentum and energy equations together with an Extended Coherent Flamelet Model (ECFM). Two different approaches in driving the…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine using CFD

Aristotle University of Thessaloniki-Savvas S. Savvakis, Elias Nassiopoulos, Dimitrios Mertzis, Zissis Samaras
  • Technical Paper
  • 2020-37-0007
To be published on 2020-06-23 by SAE International in United States
The increasing demand for lower fuel consumption and pollutant emissions favours the development of novel engine configurations. In line with this demand, the present contribution aims to investigate the sealing performance of a new concept rotary split-engine with a very promising thermal efficiency, a very low NOx emissions' level, and a much higher power density than any conventional internal combustion engine can. It uses the Atkinson cycle, a low-temperature combustion process and when it uses two pistons, symmetrically positioned around its shaft, it gives one power stroke every 180 degrees. The main focus of this work is to provide all the steps followed so far in order to ensure an efficient sealing and operation of the compression process of this engine, including the 1D & CFD simulations, CAD design & optimisation, and experimental campaign for verifying the digital results. The so-far investigation and experiments conclude that this new rotary engine can work with no oil lubrication inside the compression chamber and with much lower mechanical losses compared to the existing reciprocating engines.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Assessing the Engine-Out Pollutant Emissions of a S.I. Engine for Hybrid Powertrain Applications

Université de Bourgogne Franche-Comté-Jérémy Pelluet, Alan Keromnes, Luis Le Moyne
Université de Lyon - IFSTTAR AME ECO7-Alice Guille des buttes, Bruno Jeanneret
  • Technical Paper
  • 2020-37-0016
To be published on 2020-06-23 by SAE International in United States
Car manufacturers are introducing more and more hybrid powertrains in order to reach CO2 emissions targets and answer increasingly stringent pollutant emission regulations such as unburned hydrocarbons (HC), nitrogen oxides (NOx), carbon monoxide (CO) and particulate matter. The addition of an electric engine to a thermal engine introduces an additional degree of freedom in the energy management of the powertrain since two energy sources are available. Thus, the energy management system must also account for regulated pollutant emissions when devising an optimal energy management strategy to avoid a pollutant emission increase due to CO2 only driven optimisation. It is therefore necessary to model the influence of thermal engine operating conditions such as load and speed on these emissions to evaluate their concentration in the exhaust gases. This study presents an empiric modelling approach based on an extensive parametric study using a spark-ignition port-injection four-cylinder engine. Such a model intend to be used in the context of hybrid powertrain optimization. In order to reduce the computing costs required by ECU (Engine Control Unit), the number of…