Picosecond time-resolved laser-induced fluorescence (PITLIF) is a developing technique used to probe minor-species concentrations in flames at rates sufficient for the study of turbulent fluctuations. This method has previously been applied to the measurement of CH signals in laminar and low- Reynolds number turbulent diffusion flames. In the present work, Laser- induced Fluorescence (LIF) measurements of OH are obtained in the same flames. The peak concentrations of the hydroxyl radical provide a signal-to- noise ratio sufficient to extend the measurements to a variety of axial and radial locations relative to the flame front. The time-series measured are used to compute power spectral densities (PSDs) which provide frequency information not available from more typical probability density functions. The PSDs are compared to those from the previous CH work and to expectations for scalars in moderately turbulent flames from the literature. These measurements provide the first known PSDs of the hydroxyl radical in a low- Reynolds number turbulent nonpremixed flame.
|Number of pages
|Combustion and Flame
|Published - Dec 1998
Bibliographical noteFunding Information:
This work is supported by the U.S. Air Force Office of Scientific Research, with Dr. Julian Tishkoff as technical monitor. We are grateful for discussions with Dr. Michael Klassen (Hughes Associates, Inc.) concerning the quenching rate coefficient calculations and with Professor Jay Gore (Purdue University) concerning data analysis and interpretation.
ASJC Scopus subject areas
- Chemistry (all)
- Chemical Engineering (all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy (all)