Your Selections

Particulate matter (PM)
Show Only


File Formats

Content Types











The benefits of using Composite Bearings in Aircraft Shock Absorbers

Trelleborg Sealing Solutions-Brian Bowen, Torben A. Andersen
  • Technical Paper
  • 2019-01-1898
To be published on 2019-09-16 by SAE International in United States
This paper will use actual examples from aircraft recently introduced into service, to describe the main advantages of changing from the currently used metallic bearings, to composite bearings. Abstract: The introduction of composite bearing in a recently introduced twin aisle aircraft has resulted in: • Weight saving, by replacing bronze bearings with plastic bearings • Lowering of the particle count in the shock absorber oil, (Reduced contamination with metal particles) leading to reduced wear on seals and bearings. Qualification testing showed that Composite Bearings are able to provide longer service life than bronze bearings.

Numerical investigation of Electrostatic Spray Painting Transfer Processes for vehicle Coating

Universidade Da Beira Interior-Mohammad Reza Pendar, Jose Pascoa
  • Technical Paper
  • 2019-01-1856
To be published on 2019-09-16 by SAE International in United States
In this study we examined numerically the electrostatic spray transfer processes in the rotary bell spray applicator, which is this case implemented in a full 3D representation. The algorithm implemented and developed for this simulation includes airflow, spray dynamics, tracking of paint droplets and an electrostatic modularized solver to present atomization and in-flight spray phenomena for the spray forming procedure. The algorithm is implemented using the OpenFOAM package. The shaping airflow is simulated via an unsteady 3D compressible Navier-Stokes method. Solver for particle trajectory was developed to illustrate the process of spray transport and also the interaction of airflow and particle that is solved by momentum coupling. As the numerical results in this paper indicates dominant operating parameter voltage setting, further the charge to mass ratio and air-paint flow rate deeply effect the spray shape and the transfer efficiency (TE). The spin of the bell forced the paint to fall off from the bell edge into the high-velocity airflow. By increasing the shaping airflow more uniform distribution of mass of paint is produced but the…

Optimization of CI Engine Performance and Emissions Fueled by Blends of Alternative Fuels Methyl Ester Using Taguchi and Multi Regression Analysis

Dr. D. Y.Patil Unitech Society's-Vijay javanjal
  • Technical Paper
  • 2019-01-1893
To be published on 2019-09-16 by SAE International in United States
Today’s frenetic engine manufacturing and transportation sector and its related traces viz; noise and vibration of our modern societies has adverse effect on environment as well as all of us. Modern research affords us the opportunity to understand the subject better and to develop advance technologies. Widely immediate slogan and goal of all industries might be to improve the performance and reduce emission using alternative fuel while, make the quietest and smoothest running Engines. To, reduce the dependency on diesel fuel (Due to rapid worldwide depletion) Biodiesel is one of the immediate, alternative and complimentary solution. In the Present study, to optimize the operating parameters of the Direct Injection Single Cylinder (5.2 kw) CI engine with respect to Brake Thermal Efficiency (BTE), Carbon monoxide (CO), Oxides of Nitrogen, Hydrocarbons (HC) etc.. For this investigation, we used Biodiesel as an alternate fuel for diesel fuel which possesses low cetane number which is not sufficient to operate existing diesel engine. However, this could be combined with the diesel fuel in the form of blends. For this investigation…

Experimental investigations on engine-out emissions sensitivity to fuel injection pressure of a high-performance DISI single cylinder engine

Ferrari S.p.A.-Vincenzo Rossi, Nicola Silvestri, Massimo Medda
  • Technical Paper
  • 2019-24-0169
To be published on 2019-08-15 by SAE International in United States
In recent times complying with increasingly stringent emission regulations has become ever more challenging. While an efficient after-treatment system that includes gasoline particulate filter enables compliance with legislation requirements, lowering engine-out emissions by improving combustion system has to be considered as a crucial advantage not only in regard to pollutants emission control, but also performance. In this respect, high-performance enabling contents such as relatively large displacement, flow-capacity oriented intake ports and a limited stroke-to-bore ratio have significant drawbacks on the charge motion quality and as direct consequence on mixture formation and homogeneity. As a countermeasure, fuel injection system components as well as control strategies need to be substantially improved; on the control side the increase of fuel injection pressure coupled with optimized injection timing and splitting, has proved to be effective in reducing emissions, with special regard to particulate matter. This paper provides results of an experimental study investigating the effect of different fuel injection strategies on engine-out emissions, with special emphasis on the influence of very high fuel injection pressures (up to 50 MPa)…

Optical investigation of mixture formation in a small bore DISI engine by laser induced exciplex fluorescence (LIEF)

Technische Univ. Braunschweig-Alexander Pauls, Peter Eilts
  • Technical Paper
  • 2019-24-0133
To be published on 2019-08-15 by SAE International in United States
Legislative and customer demands in terms of fuel consumption and emissions are an enormous challenge for the development of modern combustion engines. Downsizing in combination with turbocharging and direct injection is one way to increase efficiency and therefore meet the requirements. This results in a reduction of the displacement and thus the bore diameter. The application of direct injection with small cylinder dimensions increases the probability of the interaction of liquid fuel with the cylinder walls, which may result in disadvantages concerning especially particulate emissions. This leads to the question which bore diameter is feasible without drawbacks concerning emissions as a result of wall wetting. The emerging trends towards long-stroke engine design and hybridization make the use of small bore diameters in future gasoline engines a realistic scenario. In the previous project “GDI Boundary Bore” the feasibility of an SI engine with direct injection and small bore diameter was shown by the analyses of two different cylinder head concepts (3V and 4V). For the acquirement of deeper understanding of the mixture formation in such engines…

PIV and DBI Experimental Characterization of Air flow-Spray Interaction and Soot Formation in a Single Cylinder Optical Diesel Engine using a Real Bowl Geometry Piston

GM Global Propulsion Systems-Alberto Vassallo
General Motors Italia S.r.l.-Francesco Concetto Pesce
  • Technical Paper
  • 2019-24-0100
To be published on 2019-08-15 by SAE International in United States
With demanding emissions legislations and the need for higher efficiency, new technologies for compression ignition engines are in development. One of them relies on reducing the heat losses of the engine during the combustion process as well as to devise injection strategies that reduce soot formation. Therefore, it is necessary a better comprehension about the turbulent kinetic energy (TKE) distribution inside the cylinder and how it is affected by the interaction between air flow motion and fuel spray. Furthermore, new diesel engines are characterized by massive decrease of NOx emissions. Therefore, considering the well-known NOx-soot trade-off, it is necessary a better comprehension and overall quantification of soot formation and how the different injection strategies can impact it. The present study aims to define a methodology to analyze the velocity field and consequently TKE distribution as well as to characterize soot formation inside of a real bowl geometry considering different operating conditions. For that purpose, two different optical techniques were simultaneously applied in this study. On the one hand, in-cylinder velocity fields were measured by using…

Piston Bowl Geometry Effects on Combustion Development in a high-speed light-duty Diesel Engine

Ford Motor Company-Eric Kurtz
Sandia National Laboratories-Stephen Busch, Kan Zha
  • Technical Paper
  • 2019-24-0167
To be published on 2019-08-15 by SAE International in United States
In this work, we studied the effects of piston bowl design on combustion in a light-duty direct-injection diesel engine. Two bowl designs were compared: a conventional, omega-shaped bowl and a stepped-lip piston bowl. Experiments were carried out in the SNL single-cylinder optical engine facility, with a medium-load, mild-boosted operating condition featuring a pilot+main injection strategy. CFD simulations carried out with the FRESCO platform featuring full-geometric modeling of the engine, were validated against measured in-cylinder performance as well as soot natural luminosity images. Differences in combustion development were studied using the simulation results, and sensitivities to in-cylinder flow field (swirl ratio) and injection rate parameters were also analyzed. In-cylinder mixture formation analysis showed that ignition of the pilot injection mixture develops nearly as a homogeneous adiabatic reactor, being mostly advected, not mixed, by the bowl’s swirling motion, while its timing is influenced by the local flow field. Local in-cylinder flow is also more crucial than injection parameters to igniting the main injection’s premixed fuel, as it determines the relative overlap with the high-temperature pilot ignited mixture.…

Direct Injection Compression-Ignition Diesel-Methanol Blends Engine for Non-road Applications

Guangxi Yuchai Machinery Co Ltd-Zan Zhu
Harbin Institute of Technology, Shenzhen-Guang Yao, Lei Zhou, Hao Li
  • Technical Paper
  • 2019-24-0139
To be published on 2019-08-15 by SAE International in United States
It is a promising approach to use methanol as a clean and low carbon alternative fuel for the non-road energy utilization sector and ultimately for the fight against the global climate change. This paper presents a numerical simulation of the performance and emission characteristics of neat methanol and diesel/methanol dual fuel combustion processes based on Yuchai YC6M series Heavy-Duty engine bench tests. An effective reduction of soot emission was observed with increased methanol content in the blends. Nitrogen oxide (NOx) and soot emission control strategies were also investigated at length. At high loads, if the mass fraction of methanol in the blend is controlled less than 40%, the NOx emissions of the engine would be decreased by approximately 12% while the soot emissions decreased by approximately 95%. The results indicate that the methanol engine is feasible for non-road applications.

Ultra-Lean Pre-Chamber Gasoline Engine for Future Hybrid Powertrains

FEV Europe GmbH-Knut Habermann
IFP Energies nouvelles, Institut Carnot IFPEN TE-David Serrano, Jean-Marc Zaccardi
  • Technical Paper
  • 2019-24-0104
To be published on 2019-08-15 by SAE International in United States
Lean burn gasoline spark-ignition engines can support the reduction of CO2 emissions for future hybrid passenger cars. Very high efficiencies and very low NOx raw emissions can be achieved, if relative air/fuel ratios (lambda) of 2 and above can be reached. The biggest challenge here is to assure a reliable ignition process and to enhance the fuel oxidation in order to achieve a short burn duration and a good stability for the combustion. This article aims at introducing an innovative combustion system fully optimized for ultra-lean operation and very high efficiency. Thereto, a new cylinder head concept has been realized with high peak firing pressure capability and with a low surface-to-volume ratio at high compression ratios. 1D and 3D simulations have been performed to optimize the compression ratio, charge motion and intake valve lift. Numerical calculations also supported the development of the ignition system. Stable ignition and fast flame propagation were achieved thanks to a centrally located active pre-chamber which allows to control the air/fuel ratio independently of the air/fuel ratio in the main combustion…

Ignition Delay Model of Multiple Injections in CI engines

Seoul National Univ.-Youngbok Lee, Seungha Lee, Kyoungdoug Min
  • Technical Paper
  • 2019-24-0071
To be published on 2019-08-15 by SAE International in United States
In compression ignition engines, the combustion starts after the ignition delay period from the start of injection. The degree of mixing between air and fuel during the period have an impact on the combustion characteristic such as pressure rise rate which can worsen the combustion noise. The formation of particulate matter and nitrogen oxides also can be affected. In addition, ignition delay is required when estimating the in-cylinder pressure since it can provide information about the start of combustion. Therefore, a semi-empirical and 0-dimensional ignition delay model has been developed in this study for real-time control applications. As the ignition delay consists of physical and chemical delays in CI engines, the integrated ignition delay model established in this paper considered both of them. In this study, the ignition delay could be correlated with parameters such as in-cylinder charge density, local temperature and oxygen concentration at which the fuel is injected, injection pressure and quantity of the fuel injected previously. The model could be applied to multiple injection condition which is a common strategy among the…