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A culvert representing the fuselage of an airplane was positioned 1 m downwind of the fuel pan (Figs. 2 and 3). The culvert had a nominal diameter of 2.7 m and a length of 10.7 m. It was raised 1.1 m off the ground and oriented Preliminary Results Preliminary Results Large, fully turbulent fires in the transportation and petrochemical industries often involve a large object, such as an aircraft fuselage, adjacent to or engulfed by the fire. The behaviour of the fire plume is affected by the presence of the object due to fluid dynamic and thermal interactions between the object and the fire. The presence of ambient crosswinds also adds complexity to the scenario. To date, little research is available on the interactions between fire, wind, and a large object. Therefore, a full-scale study is being performed at the University of Waterloo to characterize the thermal environment resulting from a 2 m diameter pool fire in a crosswind and adjacent to a large, cylindrical object. Pool Fires in Wind With a Large Downwind Pool Fires in Wind With a Large Downwind Object Object C. S. Lam 1 , E. J. Randsalu 1 , E. J. Weckman 1 , A. L. Brown 2 , and W. Gill 2 1 University of Waterloo, ON, Canada 2 Sandia National Laboratories, NM, USA Introduction Introduction Instrumentation Instrumentation Acknowledgements This work is supported by the Natural Sciences and Engineering Research Council of Canada and by Sandia National Laboratories of New Mexico, USA. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed- Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. Additional support from the Canadian Foundation for Innovation, the Ontario Innovation Trust, the Regional Municipality of Waterloo and the City of Kitchener is also acknowledged. Experimental Setup Experimental Setup Future Work Future Work The University of Waterloo Live Fire Research Facility (Fig. 1) contains a 20 m by 15 m test enclosure with a bank of six 2.0 m diameter fans at one end. Crosswinds of up to 13 m/s can be developed by the wind generation system. The fire was established in a 2.0 m diameter, fixed quantity pan. For each test, approximately 100 L of Jet A fuel (resulting in a 3.6 cm deep layer) was poured into the pan on top of a 10 cm deep water substrate. This amount of fuel produced burns lasting approximately 10 minutes. A diverse set of measurements was taken in these tests. The measured parameters included: 1) Temperature measurements within the fire plume were made using 48 to 86 thermocouples mounted on vertical posts or chains (Fig. 4). 2) Temperature measurements along the surface of the culvert were made using thermocouples welded to the interior surface of the culvert at 52 circumferential locations. 3) Heat flux measurements in the fire plume were made using Sandia Heat Flux Gauges (Fig. 5a), Directional Flame Thermometers (Fig. 5b), and pipe calorimeters of 0.3 m diameter (Fig. 5c). Other conventional gauges, namely Gardon gauges and thermopiles, were included for comparison purposes. 4) The rate of fuel consumption, or fuel regression rate, was measured using four different techniques. These techniques involved the use of a thermocouple rake, a sight glass, load cells, and differential pressure transducers. 5) Velocities in the thermal plume were measured using 16 Inconel bi- directional probes, with associated thermocouples (Fig. 6). 5a) 5b) 5c) Figure 5: Heat flux gauges used in the experiment, including a) the Sandia Heat Flux Gauge, b) the Directional Flame Thermometer and c) a pipe calorimeter. Visual observation showed that in crosswinds of 13 m/s, the fire hugged the ground as it passed underneath the culvert (Fig. 7a). Downwind of the object, the hot fire plume gradually curved upward as it exited the test enclosure. A similar plume trajectory was observed in crosswinds of 9 m/s. Multiple tests with the same wind speed showed that many of the variations between tests may be attributed to changes in the experimental boundary conditions, particularly the ambient temperature. These critical boundary conditions will therefore be considered when determining the overall repeatability of future measurements. Figure 7: Side view of the fire and object showing a) the fire plume passing beneath the culvert, b) the fire plume attaching to the underside of the culvert, and c) the fire plume attaching to the upwind region of the culvert. Further analysis of the measured data is needed to quantify the dependence of the measurements on the experimental boundary conditions and the effect of varying the wind speed on the thermal environment of the fire. The results will provide better insight into the hazards posed by a fire in crosswind with a large blocking object downwind of the fuel pool. Figure 2: Upwind view of the experimental setup. FUEL PAN CULVERT WIND DIRECTION Figure 6: Bi- directional velocity probes. Figure 1: University of Waterloo Live Fire Research Facility. Figure 4: Thermocouple chains downwind of the culvert. THERMOCOUPLE CHAINS 1) temperature in the fire plume, both upwind and downwind of the culvert, 2) temperature along the surface of the culvert, 3) heat flux to objects of differing thermal mass within the fire plume, 4) the rate at which fuel was consumed during each burn, and 5) velocity in the fire plume. The instrumentation that was used to measure each of these parameters is described below. 7a) 7b) 7c) At a wind speed of 4 m/s, the fire plume was seen to attach to the bottom and downwind regions of the culvert as it passed beneath the object (Fig. 7b). When the wind speed was reduced to less than 3 m/s, the flame zone became attached to the upwind region of the culvert (Fig. 7c), and much of the hot plume passed over the top of the object. Figure 3: Plan layout of the experimental setup. WIND DIRECTION FUEL PAN Ø 2 m Ø 2.7 m 10.7 m 1 m PLENUM OUTLET 5 m CULVERT
