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Mean temperatures in the chamber for inlet air temperatures of 40 °C derived from LITGS signals in 1-methylnaphthalene/air mixture using UV-excitation (open diamond symbols). The vertical dashed red lines indicate the range over which the vapour density of the 1-methylnaphthalene provided adequate signals (see text for details).) The mean temperatures in the chamber for the same inlet air temperatures of 40 °C derived from LIEGS signals using IR-excitation are shown as solid triangle symbols. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Mean temperatures in the chamber for inlet air temperatures of 40 °C derived from LITGS signals in 1-methylnaphthalene/air mixture using UV-excitation (open diamond symbols). The vertical dashed red lines indicate the range over which the vapour density of the 1-methylnaphthalene provided adequate signals (see text for details).) The mean temperatures in the chamber for the same inlet air temperatures of 40 °C derived from LIEGS signals using IR-excitation are shown as solid triangle symbols. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

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Crank angle-resolved temperatures have been measured using laser induced grating spectroscopy (LIGS) in a motored reciprocating compression machine to simulate diesel engine operating conditions. A portable LIGS system based on a pulsed Nd:YAG laser, fundamental emission at 1064 nm and the fourth harmonic at 266 nm, was used with a c.w. diode-pumpe...

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... comparison, the temperature values derived using the UV- LITGS measurements and the data derived from the IR-LIEGS mea- surements is shown in Fig. 5 . As explained above, the LITGS data is available only over the range −80-+ 80 CAD. The inlet conditions corresponding to this data included a nominal air inlet tempera- ture of 40 °C and pressure of 60 bar at TDC. The slight asymmetry in the temperature profiles reveals the effect of loss due to piston 'blow-by' during the compression ...

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