Compartment Fire Dynamics Under Differing Ventilation Conditions

点击翻译按钮获取中文摘要

The long-term objectives of this research program are to increase knowledge of key chemical, fluid dynamic and heat transfer processes that drive development, growth and toxicity in fires. Understanding these at the small scale is critical, but equally important is translation to full-scale fire situations, particularly in developing innovative fire safety solutions. Over the next 5 years, this goal will be advanced by two interconnected research thrusts to address gaps identified in the literature and by industry, regulators and the fire service: under-ventilated compartment fires and behaviour of polyurethane (PU) furniture materials. The evolution of a fire environment has important implications in design, tactical decision-making, fire protection equipment and occupant safety. Some aspects of the interactions of fires and ventilation are understood, but comprehensive scientific characterization of fires with insufficient air (oxygen) -- under--ventilated fires - has not been done. Research at UW has studied well-ventilated fires with recent work extending to under--ventilated situations. The proposed research will investigate under--ventilated furniture fires in more detail, characterizing the fuels and fire environment and examining the impact of ventilation, both mechanical and via timed opening of windows or doors during each test. Temperature, gas evolution and flow patterns will be charted in large-scale experiments in our two-storey burn structure, generating new understanding of how furniture fires develop in airtight, energy efficient structures and improved engineering models for this important class of fire. The PU foam and fabric combinations in furniture represent significant fire hazards due to their flammability, high heat release rates and propensity to support rapid flame spread.  Other challenges arise in control of PU flammability with fire retardant (FR) chemicals. Yet, PU is increasingly used in furnishings as we move toward a greener, more sustainable society. Materials are tested using prescribed methods for regulatory purposes, but results often do not translate well to performance in real fire situations. Our research has identified screening methods for fire performance which will be extended to investigate physical and chemical properties of the furniture materials used in the large-scale fires as well as the impact of new FR strategies on their burning characteristics. Results will increase understanding of the fire behaviour of furniture foam and fabric combinations and lead to new scaling laws, cost- effective screening tests and new models for fire growth and spread in modern furniture fires. This research will further establish a sound scientific basis for next generation fire safety technologies, test standards and advanced analysis tools for performance -based design. Highly qualified students will be trained to excel in the emerging performance- based fire safety market in Canada and around the world.