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Development of Valve Train Configurations Optimized for Cold Start and their Effect on Diesel Soot Emission

KIT-Karlsruhe Institute of Technology-Panagiotis Maniatis, Daniel Erforth, Uwe Wagner, Thomas Koch
  • Technical Paper
  • 2019-24-0161
To be published on 2019-08-15 by SAE International in United States
The continuous pursuit of more efficient diesel engines and the stricter emission regulations with the introduction of the Real Driving Emissions test (RDE) necessitate further investigations of heating strategies and their suitability in terms of series production. Under these circumstances heating strategies of a variable valve train for a single-cylinder research diesel engine have been first simulated and then experimentally tested at the Institute of Inernal Combustion Engines of the Karlsruhe Institute of Technology (KIT). By combining statistical experimental design (DoE) and 1-D gas exchange simulations, empirical DoE models for the design of suitable camshaft configurations have been established. After having performed a potential analysis, the most favorable configurations were used for the production and subsequently tested. The configuration with an additional opening of an outlet valve during the intake stroke (2nd Event) showed the best compromise between engine out HC/CO emissions and an efficient exhaust gas temperature increase. The strategy-related state changes in the combustion chamber when using a 2nd Event and the resulting soot behavior is the subject of the second research phase.…
 

Valve Opening and Closing Event Finalization for Cost Effective Valve Train of Gasoline Engine

Maruti Suzuki India, Ltd.-Sanjay Poonia, Amandeep Singh, Narinder Kumar, Jaspreet Singh, Shailender Sharma
Published 2019-04-02 by SAE International in United States
With more stringent emission norm coming in future, add more pressure on IC engine to improve fuel efficiency for survival in next few decades. In gasoline SI (spark ignition) engine, valve events have major influence on fuel economy, performance and exhaust emissions. Optimization of valve event demands for extensive simulation and testing to achieve balance between conflicting requirement of low end torque, maximum power output, part load fuel consumption and emission performance. Balance between these requirements will become more critical when designing low cost valve train without VVT (Variable valve timing) to reduce overall cost of engine.Higher CR (Compression ratio) is an important low cost measure to achieve higher thermal efficiency but creates issue of knocking thereby limiting low speed high load performance. The effective CR reduction by means of late intake valve closing (LIVC) is one way to achieve higher expansion ratio while keeping high geometric CR. Due to backflow at low engine speed by late IVC (Intake valve closing) it is challenging to implement late IVC without compromising low end high load performance…
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Gas Content in Lubricants of Modern Powertrain Systems - Development of a Continuous Volumetric Measurement Method

FEV Europe GmbH-Peter Theisen, Kolja Orlowsky
Institute for Combustion Engines, RWTH Aachen University-Benedikt Hammermueller, Daniel Hanciogullari
Published 2019-04-02 by SAE International in United States
Our expectations in lubrication systems applied in modern powertrains are continually rising. Beginning with the basic function of cooling and lubricating tribological contacts such as cylinder liner and piston, bearings, gears, chain drives and various valve train contacts, the oil in the lubrication system is now increasingly being used as a hydraulic fluid. Examples are (fully) variable valve trains, variable compression ratio systems or complicated transmission hydraulics. Driven by the general trend to minimize mechanical losses in order to increase the overall powertrain efficiency, the introduction of variable capacity oil pumps is commonly seen in latest engine designs. The potential to decrease oil pressure levels and volumetric oil flow in order to minimize mechanical losses on the one hand significantly complicates the reliable fulfillment of the aforementioned tasks of the lube systems on the other hand. In this context one of the core parameters for a reliable operation of modern lubrication systems in engines and transmissions is the gas content of the oil. Even though this circumstance is still partially underestimated during engine development, it…
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Development of a Highly Flexible Variable Valvetrain System for Combustion System Investigations

University of Kaiserslautern (TUK)-David Woike, Michael Guenthner, Anton Schurr
Published 2019-01-15 by SAE International in United States
For the optimization and extension of operating range of future combustion systems aiming at ultra-low emissions and high efficiency, the control of gas exchange plays a major role. Important parameters for optimization are e.g. volumetric efficiency, residual gas control, in-cylinder charge motion and precise control of the level of homogeneity or inhomogeneity of the charge as required by the particular combustion mode. In addition, advanced operating modes such as Miller or Atkinson cycle or gasoline compression ignition demand a high degree of variability in cam timing. A highly flexible variable valvetrain has been designed for the investigation and development of such new combustion processes. This novel valvetrain is based on a mechanically fully variable actuation concept using two independently rotating cam disks per valve. By this arrangement, new degrees of freedom in the design of the valve opening curve arise. For a single cylinder research engine using a four-valve cylinder head, this valvetrain has been designed in a way so that all four valves can be controlled independently, offering the possibility of e.g. inlet valve…
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2-Stroke Engine Options for Automotive Use: A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications

Saudi Aramco-Robert A. Head, Junseok Chang, Nayan Engineer
University of Bath-James W. G. Turner, Roshan Wijetunge, David W. Blundell, Paul Burke
Published 2019-01-15 by SAE International in United States
The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve.For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken.A new methodology for optimization was developed and the analysis process also took into account work done by the charging system, this being assumed to be a combination of supercharger and turbocharger to permit some exhaust waste heat recovery.As a result of this work it was found that the opposed-piston configuration provides the best attributes since it…
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Piston Detergency and Anti-Wear Performance of Non-Phosphorus and Non-Ash Engine Oil

Idemitsu Kosan Co., Ltd.-Moritsugu Kasai, Hiroaki Koshima, Yoriyuki Takashima
Published 2019-01-15 by SAE International in United States
The deposition of ash derived from engine oil on the surface of diesel particle filters (DPF) has recently been reported to degrade the performance of the DPF. It is generally known that phosphorus in engine oil is adsorbed on the surface of an automotive exhaust catalyst, reducing the performance of the catalyst. Thus, the amounts of ash and phosphorus in engine oil have been decreased. We have developed a non-phosphorus, non-ash engine oil (NPNA) that does not contain metal-based detergents or zinc dialkyldithiophosphate (ZnDTP). Various engine tests were performed, and we confirmed that under normal running conditions, the NPNA oil had a sufficiently high piston detergency and wear resistance-two important requirements for engine oil-to meet current American and Japanese standards.However, the piston detergency of NPNA required further improvement when engine running conditions were more severe. We performed a hot tube test to evaluate the piston detergency of NPNA at high temperatures and developed additives (ashless detergents) that did not contain ash (metallic elements). We then evaluated the piston detergency and valve train wear prevention of…
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Advanced Automated Analysis Methodology for Predicting the Valve Durability

Durovalves India Pvt Ltd-Jitendra Sharma, Gurunathan Ramnathan
Ricardo Software-Ankush Bhayekar, John Foy, Yogesh Umbarkar
Published 2019-01-09 by SAE International in United States
Recent advancements in IC engine and Hybrid vehicles emphasize the use of higher rated fuels with higher calorific values, leading to higher operating temperature and pressure values. This makes the design of valve train components a complex task. Typically, IC engine valves are subjected to varying stresses throughout an engine cycle. This can result in fatigue failure of valves in many applications where the supplier was deficient in advanced analysis methodologies. Considering this fact, a new technique for valve durability and life predictions has been developed using various approaches such as internal semi-empirical thermal boundary conditions calculation tool, Multibody Dynamics (MBD) and Finite Element Modelling (FEM). In this study, a bi-metallic (Stem - X45 CrSi 9 3 and Head - X50 CrMnNiNbN 21 9) exhaust valve operating under direct attack valvetrain of 1.2L inline 3-cylinder gasoline engine has been considered. Internal semi-empirical tool and literature work on gas flow has been used to predict the thermal boundary (gas side temperatures and HTCs at various locations) conditions. The predicted thermal BCs are then used to predict…
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Preparing BMW Motorrad’s Boxer Engine for the Future: Improving Performance, Driveability and Efficiency While Fulfilling Future Emission Standards

BMW Motorrad-Maximilian Oppelt, Frank Schwarz, Rüdiger Eibl, Pedro Gaitan
Published 2018-10-30 by SAE International in United States
Engine development mostly revolves around the same competing goals. With the implementation of the EU4 and EU5 emission standards for motorcycles, the difficulty of increasing performance and improving driveability and efficiency, while simultaneously fulfilling the Emission standards becomes even higher. Though the automotive industry offers a variety of solutions for the named topics, their implementation in a high performance motorcycle engine with specific needs regarding packaging, a wide operating range and full load behavior, represents a special challenge. This paper presents the approach of BMW Motorrad to meet these goals on the example of the boxer engine, focusing on the methodology throughout the development process. The gas exchange system of the engine was optimized using 1D gas dynamic simulations and 3D CFD analysis for a redesign of the valve train, ports and valves. The results of the calculations were further confirmed by experiments at the flow test bench measuring discharge coefficients and using particle image velocimetry (PIV). Combined simulation and engine testing led to a newly developed exhaust manifold enabling a faster light-off and a…
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Development of a New 1.8L Down-Speeding Turbocharged Gasoline Engine with Miller Cycle

Dongfeng Liuzhou Motor Corporation-Kefu Yao, Mingxiang Zhao
Dongfeng Motor Corporation-Yisu Ye, Libing Xu, Jinshi Wang
Published 2018-09-10 by SAE International in United States
Upcoming China 4th stage of fuel consumption regulation and China 6a emission legislation require improvement of many existing engines. This paper summarizes an upgrade of combustion system and mechanical layout for a four-cylinder engine family. Based on an existing production process for a naturally aspirated 2.0-liter gasoline engine, a 1.8-liter down-speeded and turbocharged gasoline engine is derived. Starting development by analysis of engine base geometry, a layout for a Miller-Cycle gas exchange with early closing of intake valves is chosen. Requirements on turbocharger configuration are investigated with one-dimensional gas exchange simulation and combustion process will be analyzed by means of 3D-CFD simulation. Challenging boundary conditions of a very moderate long-stroke layout with a stroke/bore-ratio of only 1.037 in combination with a cost efficient port fuel injection system and fixed valve lift profiles are considered. To compensate reduced in-cylinder charge motion of small valve lift three measures are taken. Firstly, the intake port is modified for significantly increased tumble motion at higher valve lift. This is combined with a masking of the intake valve area in…
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Investigation of a Cylinder Activation Concept for a Turbocharged Direct-Injection Gasoline Engine

University of Kaiserslautern (TUK)-Anton Schurr, Michael Guenthner, Rudolf Flierl, David Woike, Florian Mueller
Published 2018-09-10 by SAE International in United States
Today, downsizing through active displacement control is in series production using cylinder deactivation (CDA) concepts. However, current systems deactivating two cylinders of a four-cylinder engine are limited regarding the effective CO2 saving potential due to the confined usable operating range of the two-cylinder mode. Therefore, the objective of the current investigation is a three-cylinder engine with the possibility to activate an additional (fourth) cylinder. For this purpose, a four-cylinder series engine was modified to the firing order of a three-cylinder engine for the first three cylinders. The exterior cylinders 1 and 4 are operated in parallel, with the fourth cylinder deactivated in efficiency mode. Launching and idle mode are also operated with three active cylinders. Additional modifications to the valve train were carried out in order to further exploit the increased residual gas tolerance due to the load point shift. The increased ignition intervals, in conjunction with a very late intake closing timing (Atkinson cycle), improve the boundary conditions with respect to knocking tendency and lead to fuel saving potential even in the higher load…
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