Etude de la combustion de gaz de synthèse issus d'un processus de ...

Chapter 5
From figure 5.16 is observed a good reproducibility of the pressure signal for the
various ignition timings. The maximum difference between peak pressures is: 0.2 bar
for ignition timing at 5 ms BTDC (30 bar on average representing an error of 0.7%); 0.1
bar for ignition timing at 7.5 ms BTDC (38 bar on average, which represents an error of
0.03%); 0.8 bar for ignition timing at 12.5 ms BTDC (47.5 bar on average representing
an error of 1.7%).
5.2.1.4 Conclusion
tel-00623090, version 1 - 13 Sep 2011
The quality of the RCM experimental measurements was evaluated on this section
throughout a sensibility analysis of errors in measurements techniques or in the
estimation of various parameters on the main experimental results: in-cylinder pressure
and piston displacement. This analysis shows high precision of the Institute Pprime
RCM for every measured parameter also on the two strokes mode, which ensures
about the quality of the results that will be shown in the following sections.
5.2.2 In-cylinder pressure
Ignition timing of typical stoichiometric syngas-air mixtures are determined in the RCM
described in 3.1.4. Together with pressure measurements, direct visualizations from
chemiluminescence emission are also carried out to follow the early stage of the
ignition process.
Figures 5.17-5.19 show RCM experimental pressure histories of stoichiometric syngasair
mixtures and methane-air for various spark times and compression ratio ε =11. The
ignition timings tested were 5.0 ms, 7.5 ms and 12.5 ms BTDC.
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