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Kirner, Claus
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Development of a Measuring System for the Visualization of the Oil Film between the Piston and Cylinder Liner of a Gasoline Engine

SAE International Journal of Engines

Technical University of Munich, Germany-Julian Schäffer, Claus Kirner, Martin Härtl, Georg Wachtmeister
  • Journal Article
  • 03-13-02-0013
Published 2019-11-14 by SAE International in United States
The design of cylinder liners, pistons, and piston rings is subject to different conflicting goals. In addition to a loss-free seal of the combustion chamber, sufficient oil must be present between the friction partners. Both the reduction of piston assembly friction and the minimization of oil consumption are crucial to achieve the strictly defined CO2 and emission standards. To master this challenge and find the best compromise requires a lot of system-specific know-how. The automobile and engine manufacturers focus mainly on friction-reducing measures, which are analyzed with different measuring methods such as the floating-liner method, the strip-down method, or the instantaneous indicated mean effective pressure (IMEP) method. However, the interpretation of the results and the development of realistic simulation models lacks information about the oil film behavior and the film thickness. In order to gain this missing knowledge, instruments for oil film visualization and oil film thickness measurement have to be developed. In the FVV-project “Piston ring oil transport - Glassliner”, the two-dimensional laser-induced fluorescence method (2D-LIF) is used to visualize the lubricating oil film…
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Real-Time Measurement of the Piston Ring Gap Positions and Their Effect on Exhaust Engine Oil Emission

Institute of Analytical Measurement Technology Hamburg e. V.-Ann-Christin Preuss
Technical University of Munich-Benedict Paul Uhlig, Claus Kirner, Georg Wachtmeister
Published 2018-05-05 by SAE International in United States
Measurement techniques for piston ring rotation, engine oil emission and blow by have been implemented on a single-cylinder petrol engine. A novel method of analysis allows continuous and fast real-time identification of the piston ring rotation of the two compression rings, while the mass-spectrometric analysis of the exhaust gas delivers the cylinder oil emission instantly and with a high temporal resolution.Only minor modifications to the piston rings were made for the insertion of the γ-emitters, the rings rotate freely around the circumference of the piston.The idea of this setup is that through online observation at the test bench, instant feedback of the measured variables is available, making it possible to purposefully select and compare measurement points. The high time resolution of the measurement methods enables the analysis of dynamic effects.In this article, the measurement setup and evaluation method is described. Results monitoring the ring gap positions and the exhaust engine oil emission are discussed together with results of blow-by measurements for different speeds and loads. With the production piston assembly, only minor rotational movement of…
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