Radiation Transport Measurements in Methanol Pool Fires With Fourier Transform Infrared Spectroscopy.
Radiation Transport Measurements in Methanol Pool Fires
With Fourier Transform Infrared Spectroscopy.
NIST GCR 09-922; 138 p. January 2009.
Sponsor:National Institute of Standards and Technology,
pool fires; FT-IR; methanol; heat transfer; equations;
combustion; absorption; experiments; spectroscopy; fuel
supply; temperature measurements; vapor phases;
transmission; mass burns; burning rate; gas
chromatography; carbon dioxide; carbon monoxide;
radiative heat transfer; spectral absorptivity; flame
Pool fires rely on heat feedback from the combustion
process to the liquid surface to vaporize the fuel. This
coupled relationship determines the fuel burning rate
and thus the fire structure and size. Radiative heat
transfer is the dominant heat feedback in large pool
fires. Species concentrations and temperatures have
large influence on the radiative heat transfer in the
fuel rich-core between the flame and the pool surface.
To study radiative transport in the fuel-rich core, an
experimental method was developed to measure spectral
absorption through various pathlengths inside a 30 cm
diameter methanol pool fire by using a Fourier Transform
Infrared Spectrometer with N2 purged optical probes. The
measured spectra are used to estimate species
concentration profiles of methanol, CO, and CO2 in the
fuel rich core by fitting predictions of a spectrally
resolved radiation transport model to the measured
spectra. Results show the importance of reliable
temperature measurements for fitting the data and the
need for further measurements to further understand the
structure of fuel rich cores in pool fires.