http://hdl.handle.net/1903/2241 Tue, 21 May 2013 08:57:02 GMT 2013-05-21T08:57:02Z http://hdl.handle.net/1903/13657 Title: OBSERVED BEHAVIOR OF PLATOON DYNAMICS DURING HIGH-RISE STAIRWELL EVACUATIONS Authors: Baker, Matthew Daniel Abstract: This research analyzes the phenomena of grouping or platooning during the evacuation of seven stairwells within four different high-rise buildings. The purpose of this research is to investigate the changes occurring to platoons as they descend the stairs in order to incorporate the results into computer egress models. Platoons are found to travel in three distinct patterns: elongation, compression, and equilibrium. Also, platoons are found to remain unchanged, add new occupants, merge with other platoons, or fragment during their descent within a stairwell. The results demonstrate that a trend exists between patterns of platoon elongation leading to fragmentation and platoon compression leading to platoons merging. The majority of the platoons identified are found to consist of one person and remain unchanged as they descend between floors. Finally, a qualitative comparison between the platoons analyzed and the platoons identified in the behavioral computer egress model Pathfinder, is presented. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/1903/13657 2012-01-01T00:00:00Z http://hdl.handle.net/1903/13653 Title: Experimental and Computational Analysis of the Fire Suppression Effectiveness of Halon 1301 Replacements Authors: Pagliaro, John Leonard Abstract: Experimental and computational work was performed to help understand why sub-inerting concentrations of HFC-125 (C2HF5) produced overpressures in the FAA aerosol can explosion test. The fire suppression performance of HCFC-123 (C2HCl2F3) was also investigated to determine whether it may perform better than HFC-125. Thermodynamic analysis shows that both agents increase the overall heat release for lean mixtures containing the aerosol can contents. HFC-125 also increases the overall reaction rate when added to lean mixtures. The overall reaction rate of mixtures containing HCFC-123 is generally lowered when sub-inerting concentrations are added. Experimental results showed that HCFC-123 has a lower minimum inerting concentration (8.9%) than HFC-125 (13.5%). Mixtures containing HCFC-123 were found to produce peak pressures in the 2 L chamber that were estimated to cause overpressures in the FAA chamber. Nitrogen dilution resulting in 20% oxygen in air was successful at eliminating the overpressure of mixtures containing HCFC-123. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/1903/13653 2012-01-01T00:00:00Z http://hdl.handle.net/1903/13574 Title: ASSESSMENT OF NATURAL VERTICAL VENTILATION FOR SMOKE AND HOT GAS LAYER CONTROL IN A RESIDENTIAL SCALE STRUCTURE Authors: Opert, Kelly Abstract: In firefighting, ventilation tactics are used to increase visibility for firefighter rescue and fire suppression operations, to increase survivability of the occupants of the structure, and to decrease property damage. Improperly implemented ventilation tactics or unplanned, fire-induced ventilation can lead to rapid changes in fire behavior creating fatal conditions inside a building for occupants and firefighters. In this set of experiments, measurements were made within a single, full scale compartment varying the fire size and the ceiling vent conditions between no vents, one 1.2 m by 1.2m (4' by 4') vent, and two combined 1.2 m by 1.2m (4' by 4') vents. The objective was to assess the vents' ability to relieve smoke and the hot gas layer. Thirty-two experiments were conducted using natural gas. These fires were allowed to burn until conditions within the enclosure reached steady state. With one open vent, the hot gas layer was not fully vented. With two open vents, the hot gas layer was fully vented for all three fires sizes. Simulations of the natural gas experiments were produced using the National Institute of Standards and Technology's Fire Dynamics Simulator in order to explore how well the experiments were simulated based on the same fire sizes and vent conditions. The simulated steady state hot gas layer depths were significantly less than the experimental depths in the doorway when both vents were open, due to a discrepancy in whether or not a hot gas layer existed. The steady state hot gas layer temperatures were significantly under-predicted near the burner when both vents were open (meaning the simulated temperatures were cooler than the measured temperatures) and over-predicted in the doorway when one vent was open and two vents were open (meaning the simulated temperatures were hotter than the measured temperatures). Two additional experiments were conducted using sleeper sofas as fuel, in order to evaluate the differences between controlled natural gas fires and furniture. Neither one open vent nor two open vents was enough to raise the hot gas layer interface height. In the experiment with two sofas, two open vents did reduce the hot gas layer temperature at the doorway by as much as 300 °C (600 °F), but the temperature was still in excess of 200 °C (400 °F). In conclusion, the minimum vertical vent size of one 1.2 m by 1.2m (4' by 4') that firefighters are instructed to use does not remove all hazards, even in a 0.5 MW fire. More discussion is needed in the fire service to define the goals of vertical ventilation and how to best address each goal. More validation of the Fire Dynamics Simulator is needed before vertical ventilation can be accurately simulated in a multi-room structure fire. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/1903/13574 2012-01-01T00:00:00Z http://hdl.handle.net/1903/13573 Title: EFFECTS OF RADIANT HEAT FLUX ON CLEAN AGENT PERFORMANCE FOR CLASS-C STANDARDS Authors: Patel, Romil Abstract: This thesis investigates the effects of radiant heat flux on clean agent extinguishing concentrations. This data is sought to support standards that address Class C hazards. Using the REED apparatus, performance of clean agents IG-100, IG-55, IG-541, HFC-125, HFC-227ea and FK-5-1-12 at heat flux levels of 0-40 kW/m2 was examined. It was found that clean agent extinguishing concentrations increased with an added heat flux. An alternate method of testing with the REED apparatus was also examined. Clean agents examined in the test were IG-100, IG-55, IG-541, HFC-125 and HFC-227ea at heat flux levels from 0-5 kW/m2. It was found that clean agent extinguishing concentrations increased by 33 to 45 percent from the original testing method. The new testing method was also found to be more repeatable and less time consuming. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/1903/13573 2012-01-01T00:00:00Z