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

Experimental set ups and diagnostics
Figure 3.16 represents the kinetic turbulent energy. The maximum of kinetic energy is
obtained 2-3 ms before TDC. It is followed by a rapid decrease that reflects both the
overall decrease of the turbulent kinetic energy but also the convection of the fastest
zones outside the measured field.
tel-00623090, version 1 - 13 Sep 2011
Figure 3.16– Kinetic energy (left) and turbulence intensity (right). Reprinted from Strozzi, (2008)
The turbulent intensity calculated in zone 1 is moderate, with a value of about 20% with
minor variations over time. One should remind that this value corresponds to a high
velocity turbulent zone. Furthermore, figure 3.16 suggests turbulence intensity much
higher at the interface between the turbulent zones and low velocity zones.
3.2.6 Schlieren photography
Schliere (pl. Schlieren) is a German word denoting optical inhomogeneity in an
otherwise transparent region. Such inhomogeneity causes refraction of light, which can
be displayed on a screen and used as a source of information on the disturbance
(Chomiak, 1990). The method is illustrated in Figure 3.17.
A,C E E D F
G H
A,C E D,G
F
H
Figure 3.17– Typical (top) and single-lens (bottom) schlieren systems.
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