In-cylinder Surface Thermometry using Laser Induced Phosphorescence
Författare
Summary, in English
Surface temperature in internal combustion engines is of high interest when studying heat losses. Two approaches for
retrieving the surface temperatures are thermocouples and Laser Induced Phosphorescence, LIP. This study aims to
analyze LIP as a technique for measuring surface temperature in internal combustion engines. The motivation for this
study is the need for accurate surface temperatures which can be used by predictive models and increase knowledge
about heat transfer.
In this work LIP measurements have been carried out in two optical engines. In the first engine a thermographic
phosphor was applied on top of a metal piston. The second engine was fitted with a quartz liner which was coated with
phosphor material. Several coating thicknesses have been tested and the LIP temperature was extracted from both
opposing sides of the phosphor. Both engines were run in HCCI mode with reference fuels and electrically heated air.
In a previous publication, the authors showed that a layer of phosphor can show different temperatures i.e. a higher
temperature on the side facing the cylinder gas than on the side facing the wall. In this study it is shown which thickness
is needed to accurately present the temperature for typical engine combustion. With an increasing thickness of the
phosphor material, the surface gets gradually insulated and the phosphor temperature reading becomes inaccurate.
LIP measurements from a quartz ring and a metal piston have been compared and the temperature increase during
combustion is similar although the heat conductivity of quartz is 40-200 times smaller than the metal piston.
Measurements with thermocouples often show a lower temperature increase than what is seen in the LIP results. The
difference in heat conductivity between the phosphor coating and the underlying surface is of importance for
understanding what temperature is actually measured.
retrieving the surface temperatures are thermocouples and Laser Induced Phosphorescence, LIP. This study aims to
analyze LIP as a technique for measuring surface temperature in internal combustion engines. The motivation for this
study is the need for accurate surface temperatures which can be used by predictive models and increase knowledge
about heat transfer.
In this work LIP measurements have been carried out in two optical engines. In the first engine a thermographic
phosphor was applied on top of a metal piston. The second engine was fitted with a quartz liner which was coated with
phosphor material. Several coating thicknesses have been tested and the LIP temperature was extracted from both
opposing sides of the phosphor. Both engines were run in HCCI mode with reference fuels and electrically heated air.
In a previous publication, the authors showed that a layer of phosphor can show different temperatures i.e. a higher
temperature on the side facing the cylinder gas than on the side facing the wall. In this study it is shown which thickness
is needed to accurately present the temperature for typical engine combustion. With an increasing thickness of the
phosphor material, the surface gets gradually insulated and the phosphor temperature reading becomes inaccurate.
LIP measurements from a quartz ring and a metal piston have been compared and the temperature increase during
combustion is similar although the heat conductivity of quartz is 40-200 times smaller than the metal piston.
Measurements with thermocouples often show a lower temperature increase than what is seen in the LIP results. The
difference in heat conductivity between the phosphor coating and the underlying surface is of importance for
understanding what temperature is actually measured.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Sidor
482-487
Publikation/Tidskrift/Serie
[Host publication title missing]
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Dokumenttyp
Konferensbidrag
Förlag
Japan Society of Mechanical Engineers
Ämne
- Other Mechanical Engineering
- Atom and Molecular Physics and Optics
Nyckelord
- Heat transfer
- surface temperature
- HCCI
- laser induced phosphorescence (LIP)
Conference name
The Eighth International Conference on Modeling and Diagnostics for Advanced Engine Systems
Conference date
2012-07-23 - 2012-07-26
Conference place
Fukuoka, Japan
Status
Published