Affiliations: School of Mechanical and Aerospace Engr., Seoul
National University, Kwank-Gu, Seoul 151-742, Korea | School of Mechanical and Aerospace Engr., Seoul
National University, Kwank-Gu, Seoul 151-742, Korea. E-mail:
ybyoon@snu.ac.kr | Department of Aerospace Engineering, Konkuk
University, Gwangjin-Gu, Seoul 143-701, Korea.
Abstract: In the present study, we used a simultaneous PIV-OH PLIF measurement
to acquire the strain rate and the chemical intensity and suggested a new
combustion phase diagram. This simultaneous measurement was used to analyze the
flame structure and to classify the combustion regimes of the opposed impinging
jet combustor according to the change of the orifice diameters at the
pre-chambers. The shear strain rates were obtained from the velocity
measurement by PIV to represent flow characteristics and the OH radical
intensities were obtained from OH PLIF to indicate the flame characteristics.
When the strain rate and OH intensity at each point of the measurement zones
are plotted at the strain rate-chemical intensity diagram, the distribution of
each case showed the characteristics of each flame regime. The change of
combustor condition made different distribution in the combustion phase
diagram. As the orifice diameter of the pre-chamber decreases, well-mixed
turbulent flames are produced and the combustion phase is moved from the
moderated turbulence regime to the thickened reaction regime.
