- Author
- Weekman, E. J.
- Title
- Structure of the Flowfield Near the Base of a Medium-Scale Pool Fire.
- Coporate
- Waterloo Univ., Ontario, Canada
- Report
- Thesis, 1987, 319 p.
- Keywords
- pool fires | flow fields | acetone | flow visualization | velocity | temperature | schlieren photography | laser doppler anemonmetry | temperature field | thermocouples | air entrainment | equations | temperature measurements
- Identifiers
- flame zone; data acquisition
- Abstract
- An experimental study was conducted to examine the structure of the continuous flame zone of a medium-scale acetone pool fire. The large-scale structures which govern air entrainment and mixing in the lower regions of the fire and impart to the the fire its characteristic oscillation frequency were examined. Based on the experimental results, a model was formulated which described the sequence of steps in the formation and rising of these structures. The investigation included flow visualization and simultaneous measurements of velocity and temperature. Schlieren and direct photography were employed to determine regions in the continuous flame zone where the mixing processes were occurring, then Laser Doppler Anemometry was used to measure time-averaged and fluctuating velocities in those regions. The corresponding temperature field was measured using fine-wire thermocuoples. Mean and rms values of velocity and temperature, together with probability density functions and power spectral density distributions for each variable constitute the most comprehensive set of measurements taken in the flowfield aboved a medicum-scale pool fire to date. In addition, the simultaneous measurements were combined to calculate joint velocity-temperature statistics and mean turbulent flux terms. A simplified control volume analysis was developed so that time-averaed results could be used to evaluate the total mass, momentum and energy fluxes through the continuous flame zone, as well as the rate of air entrainment into the lower regions of the fire. This model made it possible to study the effects of various terms in the governing equations of motion.