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Gohl M.,APL Automobil Pruftechnik Landau GmbH | Brandt S.,University of Kassel | Wittler M.,RWTH Aachen | Budde M.,RWTH Aachen | And 7 more authors.
SAE International Journal of Fuels and Lubricants | Year: 2010

Partly competing objectives, as low fuel consumption, low friction, long oil maintenance rate, and at the same time lowest exhaust emissions have to be fulfilled. Diminishing resources, continuously reduced development periods, and shortened product cycles yield detailed knowledge about oil consumption mechanisms in combustion engines to be essential. There are different ways for the lubricating oil to enter the combustion chamber: for example as blow-by gas, leakage past valve stem seals, piston rings (reverse blow-by) and evaporation from the cylinder liner wall and the combustion chamber. For a further reduction of oil consumption the investigation of these mechanisms has become more and more important. In this paper the influence of the mixture formation and the resulting fuel content in the cylinder liner wall film on the lubricant oil emission was examined. The oil emission behavior was investigated in a single cylinder spark ignition engine under different mixture formation conditions with Direct Injection (DI) and with Port Fuel Injection (PFI). The oil film thickness and the fuel content in the film were observed using the Light Induced Fluorescence (LIF) technique. The light accessed the cylinder liner through a silica glass window at significant locations which were determined by CFD-simulation. Moreover in-cylinder experiments have been carried out to measure the composition of the oil film and the hydrocarbon emissions by online mass spectrometry. Further numerical simulation results and fundamental laboratory experiments contributed to a more detailed understanding of the interrelation between mixture formation and oil emission. © 2010 SAE International.

Krahl J.,Coburg University of Applied Sciences | Munack A.,Johann Heinrich Von Thunen Institute | Ruschel Y.,APL Automobil Pruftechnik Landau GmbH | Bunger J.,BGFA Research Institute of Occupational Medicine
SAE International Journal of Fuels and Lubricants | Year: 2010

Rapeseed oil methyl ester, two common fuels and one artificial blend were investigated their effects on particulate emissions. A heavy-duty diesel engine equipped with a diesel oxidation catalyst (DOC) was used for this test. Properties such as composition of particulate matter, as well as particle size and number distributions were measured using an electronic low pressure impactor (ELPI) and a scanning mobility particle sizer (SMPS) besides the regulated emissions: carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM). Furthermore investigations were carried out regarding the influence of dilution temperature on particle number distribution measured via SMPS. Studies were carried out with and without a DOC. Additionally the mutagenic potency of the particulate and gaseous emissions was determined using the Ames test. RME led to lower regulated emissions than common diesel fuel with exception of NOx. With DOC a further decrease in emissions was obtained. On the other hand also a light increase of NOx emissions was observed when the DOC was used. Regarding the non-regulated emissions RME showed the lowest values compared with the other fuels. In measurements via SMPS higher emissions of particles in the nuclei mode were observed for RME compared to the other three fuels. In course of investigations regarding the composition of particulate matter from raw exhaust gas (PMreg) as well as investigations of the influence of dilution temperature it could be demonstrated that these nuclei particles mainly result from emission of unburned fuel. The mutagenicity of all PM extracts was very low compared to prior studies. A further slight decrease of the mutagenic potential was obtained when using a DOC. © 2009 SAE International.

Muller G.,APL Automobil Pruftechnik Landau GmbH | Stern D.,APL Automobil Pruftechnik Landau GmbH | Rebholz C.,APL Automobil Pruftechnik Landau GmbH | Muller U.,APL Automobil Pruftechnik Landau GmbH
Tribologie und Schmierungstechnik | Year: 2015

The requirement to optimize the tribological behavior of friction components in the automotive industry will increase in the future furthermore. The need to develop friction partners existing of new materials, coatings and state of the art oil formulations requires online techniques to determine the wear characteristics of the systems. The ICP-OES is a powerful tool to support these developments as an amendment to the well established RNT technique.

Gohl M.,APL Automobil Pruftechnik Landau GmbH | Adams D.,Ford Motor Company
SAE International Journal of Fuels and Lubricants | Year: 2010

The improvement of engine efficiency, without adversely affecting oil consumption, blowby-gas, wear, or costs are desirable objectives for today's engine manufacturers as they strive to improve engine performance while trying to meet increasingly stringent emissions regulations. In this context the development of piston ring designs as well as optimized surface texturing and lubricating oil formulation is of main interest. The combination of simulation programs and the application of dynamic online oil emission measurement techniques lead to a target oriented development and a deeper understanding of the mechanisms causing oil consumption. The paper presents the results of the experimental and theoretical investigations of oil consumption mechanisms. A mass spectrometric method developed by the author et al., was used to measure the online oil emission in the exhaust gas by means of direct analysis of the lubricating oil molecules. Running-in tests were conducted with a four-cylinder gasoline engine to observe the changing tribological performance due to variations in cylinder surface topography and piston ring geometry. In this context the results of the oil emission of a conventional honed surface in comparison with an optimised structure is discussed. Dynamic engine operation, as well as complete engine oil emission maps over different steady state conditions were evaluated. © 2010 SAE International.

Magar M.,MOT GmbH | Spicher U.,MOT GmbH | Palaveev S.,Caterpillar Inc. | Gohl M.,APL Automobil Pruftechnik Landau GmbH | And 3 more authors.
SAE International Journal of Engines | Year: 2015

In the present paper the results of a set of experimental investigations on LSPI are discussed. The ignition system of a test engine was modified to enable random spark advance in one of the four cylinders. LSPI sequences were successfully triggered and exhibited similar characteristics compared to regularly occurring pre-ignition. Optical investigations applying a high speed camera system enabling a visualization of the combustion process were performed. In a second engine the influence of the physical properties of the considered lubricant on the LSPI frequency was analyzed. In addition different piston ring assemblies have been tested. Moreover an online acquisition of the unburned hydrocarbon emissions in the exhaust gas was performed. The combination of these experimental techniques in the present study provided further insights on the development of LSPI sequences. In particular strong evidence enabling the identification of the fundamental trigger of premature, local auto-ignitions has been found. The results of the optical investigations reveal that pre-ignition is initiated in the immediate vicinity of glowing solid particles. The particles either result from the flaking of deposits or as a consequence of the contamination of the combustion chamber subsequent to a pre-ignition event. Copyright © 2015 SAE International.

Behn A.,TU Hamburg - Harburg | Feindt M.,TU Hamburg - Harburg | Matz G.,TU Hamburg - Harburg | Krause S.,TU Hamburg - Harburg | Gohl M.,APL Automobil Pruftechnik Landau GmbH
SAE Technical Papers | Year: 2015

The limitation of fuel entry into the oil sump of an internal combustion engine during operation is important to preserve the tribological properties of the lubricant and limit component wear. For observation and quantification of the effects leading to fuel entry, a highly sensitive and versatile measurement system is essential. While oil sampling from the sump followed by laboratory analysis is a common procedure, there is no system for automatic sampling of all the positions and fast online analysis of the samples. For the research project 'Fuel in Oil', a measurement system was developed especially for the described tasks. The system is placed next to the engine in the test cell. Sampling points are the target point of the fuel injector jet and the liner below, the oil sump and the crankcase ventilation system. The system consists of a microliter volume and an aerosol sampling setup, a probe evaporator, an isothermal gas chromatograph and a triple quadrupole mass spectrometer with a modified ion source. To quantify the fuel emission from the cylinder wall into the exhaust, an online exhaust gas measurement was carried out using a direct inlet system with the same mass spectrometer. With the use of the described setup, it was possible to observe and quantify the effects leading to fuel entry into the oil sump as well as fuel leaving the sump. Copyright © 2015 SAE International.

Bregar J.,University of Kassel | Rienacker A.,University of Kassel | Gohl M.,APL Automobil Pruftechnik Landau GmbH | Knoll G.,IST GmbH Aachen
SAE Technical Papers | Year: 2015

Increased quantities of fuel in the lubricating oil of CI engines pose a major challenge to the automotive industry in terms of controlling the oil aging and the wear caused by dilution. Due to a lack of methods to calculate the oil-fuel-composite transport across the ring pack, predicting the fuel ratio in the oil sump has been an extremely challenging task for engine manufacturers. An accurate and computationally efficient simulation model is critical to predict the quantity of fuel diluted in the oil in the preliminary development stage of automotive engines. In this work, the complex composite transport across the piston ring pack was reduced to a simple transport model, which was successfully implemented into a multi-body simulation of the ring pack. The calculation domain was partitioned into two parts, the ring grooves and the piston lands. Inside the grooves the oil flow caused by the pumping and squeezing action of the piston rings was calculated using the Reynolds equation. On the piston lands simplified Navier-Stokes equations were used to calculate the oil flow caused by the inertia force and dragging action of the blow-by gases. This reduced model enables a calculation of the composite transport in a minimum of time and is therefore well suited for DoE. The main oil flow was observed to be driven by the dragging action of the blow-by gases. The computed integral volume of fuel leaking into the oil sump was successfully validated against the measured value of accompanying experiments. © 2015 SAE International.

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