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Laser-Induced Phosphorescence and the Impact of Phosphor Coating Thickness on Crank-Angle Resolved Cylinder Wall Temperatures

SAE International Journal of Engines

Div. of Combustion Engines, Lund Institute of Technology-Peter Andersson, Martin Algotsson, Martin Tuner, Bengt Johansson
Div. of Combustion Physics, Lund Institute of Technology-Christoph Knappe, Mattias Richter, Johannes Linden, Marcus Alden
  • Journal Article
  • 2011-01-1292
Published 2011-04-12 by SAE International in United States
In order to further improve the energy conversion efficiency in reciprocating engines, detailed knowledge about the involved processes is required. One major loss source in internal combustion engines is heat loss through the cylinder walls. In order to increase the understanding of heat transfer processes and to validate and generate new heat transfer correlation models it is desirable, or even necessary, to have crank-angle resolved data on in-cylinder wall temperature.Laser-Induced Phosphorescence has proved to be a useful tool for surface thermometry also in such harsh environments as running engines. However, the ceramic structure of most phosphor coatings might introduce an error, due to its thermal insulation properties, when being exposed to rapidly changing temperatures. In this article the measurement technique is evaluated concerning the impact from the thickness of the phosphorescent layer on the measured temperature. Experiments with different layer thicknesses are performed both during motored and fired operation of a HCCI engine. The results reveal a need for caution when applying the technique for in-cylinder measurements.
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Ion Current Sensing for HCCI Combustion Feedback

Div. of Combustion Engines, Lund Institute of Technology-Andreas Vressner, Per Tunestål, Bengt Johansson
Dept. of Automatic Control, Lund Institute of Technology-Johan Bengtsson, Rolf Johansson
Published 2003-10-27 by SAE International in United States
Measurement of ion current signal from HCCI combustion was performed. The aim of the work was to investigate if a measurable ion current signal exists and if it is possible to obtain useful information about the combustion process. Furthermore, influence of mixture quality in terms of air/fuel ratio and EGR on the ion current signal was studied. A conventional spark plug was used as ionization sensor. A DC voltage (85 Volt) was applied across the electrode gap. By measuring the current through the gap the state of the gas can be probed. A comparison between measured pressure and ion current signal was performed, and dynamic models were estimated by using system identification methods.The study shows that an ion current signal can be obtained from HCCI combustion and that the signal level is very sensitive to the fuel/air equivalence ratio. The most important result from this study is that the ion current signal proved to be an excellent indicator of the actual combustion timing which is crucial piece of information for HCCI control.
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The Effect of In-Cylinder Flow and Turbulence on HCCI Operation

Div. of Combustion Engines, Lund Institute of Technology-Magnus Christensen, Bengt Johansson
Published 2002-10-21 by SAE International in United States
The effect of in-cylinder flow and turbulence on HCCI operation has been experimentally studied by changing the combustion chamber geometry and the swirl ratio. Four different levels of turbulence were achieved, by altering the swirl ratio both for a high turbulent square bowl-in-piston combustion chamber and for a low turbulent disc combustion chamber. The swirl ratio was altered by using different inlet port designs.The results showed that the combustion chamber geometry plays a large role in HCCI combustion. With the same operating conditions, the combustion duration for the square bowl-in-piston combustion chamber was much longer compared to the disc combustion chamber. On the other hand, a moderate change in swirl ratio proved to have only modest effect on the combustion process. With early combustion timing, the gross indicated efficiency was higher when the square bowl-in-piston combustion chamber. Although, with late combustion timing, the disc combustion chamber gave the highest efficiency. When the disc combustion was used, the indicated efficiency was rather unaffected by a change in swirl ratio. However, with the square bowl-in-piston combustion chamber…
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The Effect of Combustion Chamber Geometry on HCCI Operation

Div. of Combustion Engines, Lund Institute of Technology-Magnus Christensen, Bengt Johansson
Scania CV-Anders Hultqvist
Published 2002-03-04 by SAE International in United States
The effect of the combustion chamber geometry and the turbulence on Homogeneous Charge Compression Ignition (HCCI) operation has been experimentally investigated. A high turbulent square bowl in piston combustion chamber has been compared with a low turbulent disc combustion chamber.The results showed that the combustion chamber geometry plays large role for HCCI combustion. At the same operating conditions, the peak combustion rate for the square bowl combustion chamber was much lower compared to the disc combustion chamber. The combustion duration was in some cases almost a factor two longer for the square bowl combustion chamber. The lower combustion rate with the square bowl was due larger heat losses, lower combustion efficiency and higher turbulence.
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