《火灾科学与城市安全》课程教学资源（参考教材）James G. Quintiere - Principles of Fire Behavior（1997）.pdf_P16-P20

Chapter1The Evolution of FireScienceEurope during a world tour to review the status of fire science.7A perfect corre-lation among all of the six tests should produce thesamerankingforthe twenty-four materials,a 45°straight line correlation.For example, the number 6 materialshould be ranked as 6 by all the testsfor a perfect correlation of flammability.Thetests decidedly do not correlate! The results are not consistent, giving ambiguitytothetermflammability.Perhapsitisappropriatethatinthebookintendedtopresent accurate prose (The Elements of Style byW.Strunk Jr.and E.B.White),thewordflammableislistedamong thosemisused:Flammable. An oddity, chiefly useful in saving lives. The common wordmeaning"combustible"is inflammable.Butsome people arethrown offbythe in-and think inflammable means"not combustible."For this reason,trucks carryinggasoline or explosives are nowmarked FLAMMABLE.Unlessyou are operating such a truck and hence are concerned with the safety ofchildren and illiterates,use inflammable.sWe do not currently have a universal test procedure to establish flammability or,alternatively,inflammability.These tests are reflections of our misuse of theword.NOTETheannualcostsoffireare notinsignificant,butbecauseoftherelativelylowfrequency of fire compared to other societal threats, they are not fully recognized.it has been estimatedInfact, statistics arelikelyto beinaccurateand incomplete,Moreover,fire safetythattheannual costofcosts do not increase the productivity of the economy; they are a drag on the econ-fire in the Unitedomy.When they become too great, more attention will be made to minimizingStates is $85 billion.them. It has been estimated that the annual cost of fire in the United States is s85billion.Thistotal includespropertyloss,business interruption,product liabili-ty,insuranceadministrativevice(paid),andfireprotectionincon-costsrestructionandequipment.Table1-2shontageofmajorcosts-propertyINOTEn($2billion,U.S.A.),fireloss(s10billion,U.S.A.,fire3service (~s10billion,U.S.A.)ministrative costs (~s6 billion,It istypical for aU.S.A.)forarangeofcountriesscaledtorossdomesticproducts(GDP).AsTneircountry to invest nearlycan be seen, it is typical for manyydevelopedcountriestoinvestnearly1%ofits1% of its GDPfor fire-GDP in fire-related costs.It could be as high as 2% if more complete accountingrelated costs.weredone.Unfortunately,not even1% or 2%of these costs are invested inimproving our knowledge of the technology of fire safety.Lessons are not justlearned from history,but must also be analyzed using the science offire.Nevertheless, future disasters will shape the course offire safety.In devel-INOTEoping nations,high-rise buildings are being builtto heights that dwarf current lev-Future disasters willels.It is possible that thousands ofoccupants will be seriously affected orkilledshape the course of fireby a fire disaster in a high-rise building, Future living arrangements in outer spacesafety.under low gravity and in underground and undersea structures will present un-expected fire hazards.Fire affecting radioactive operations and toxic waste stor-age sites will present hazards of new dimensions.Despite improvements in firesafety technologies, there will be new surprises in the technological advance-ments of society

Chapter 1 The Evolution of Fire Science ■ NOTE It has been estimated that the annual cost of fire in the United states is $85 billion. NOTE It is typical for a country to invest nearly 1% of its GDP for firerelated costs. ■ NOTE Future disasters will shape the course of fire safety. Europe during a world tour to review the status of fire science. 7 A perfect correlation among all of the six tests should produce the same ranking for the twentyfour materials, a 45° straight line correlation. For example, the number 6 material should be ranked as 6 by all the tests for a perfect correlation of flammability. The tests decidedly do not correlate! The results are not consistent, giving ambiguity to the term flammability. Perhaps it is appropriate that in the book intended to present accurate prose (The Elements of Style by W. Strunk Jr. and E. B. White), the word flammable is listed among those misused: Flammable. An oddity, chiefly useful in saving lives. The common word meaning "combustible" is inflammable. But some people are thrown off by the in- and think inflammable means "not combustible." For this reason, trucks carrying gasoline or explosives are now marked FLAMMABLE. Unless you are operating such a truck and hence are concerned with the safety of children and illiterates, use inflammable.8 We do not currently have a universal test procedure to establish flammability or, alternatively, inflammability. These tests are reflections of our misuse of the word. The annual costs of fire are not insignificant, but because of the relatively low frequency of fire compared to other societal threats, they are not fully recognized. In fact, statistics are likely to be inaccurate and incomplete. Moreover, fire safety costs do not increase the productivity of the economy; they are a drag on the economy. When they become too great, more attention will be made to minimizing them. It has been estimated that the annual cost of fire in the United States is $85 billion. 9 This total includes property loss, business interruption, product liability, insurance administrative costs, fire service (paid), and fire protection in construction and equipment. Table 1-2 shows the percentage of major costs-property loss ($10 billion, U.S.A.), fire protection in construction ($20 billion, U.S.A.), fire service (-$10 billion, U.S.A.) and insurance administrative costs (-$6 billion, U.S.A.)-for a range of countries scaled to their gross domestic products (GDP). As can be seen, it is typical for many developed countries to invest nearly 1 % of its GDP in fire-related costs. It could be as high as 2% if more complete accounting were done. Unfortunately, not even 1 % or 2% of these costs are invested in improving our knowledge of the technology of fire safety. Lessons are not just learned from history, but must also be analyzed using the science of fire. Nevertheless, future disasters will shape the course of fire safety. In developing nations, high-rise buildings are being built to heights that dwarf current levels. It is possible that thousands of occupants will be seriously affected or killed by a fire disaster in a high-rise building. Future living arrangements in outer space under low gravity and in underground and undersea structures will present unexpected fire hazards. Fire affecting radioactive operations and toxic waste storage sites will present hazards of new dimensions. Despite improvements in fire safety technologies, there will be new surprises in the technological advancements of society

Chapter1TheEvolutionofFireScienceentist, who brought a unification and clarity to the subject that is still appreciat-heat transfered today.Heattransfer alsohad its roots in the early1800s.JosephFourier,a gen-thetransportoferal in Napolean's army,formulated the law of heat conduction that forms theenergyfromahigh-totheoreticalbasis of the field.But heattransfer in fluids had to await the develop-low-temperaturement of modern fluid mechanics in the late 1800s when O.Reynold's pioneeringobjectwork on turbulent flow laid the basis for engineering analysis. In the 1900s,Theodore von Karman and others advanced the subjectofaerodynamics,whichfluid mechanicspaved the wayfor a more complete framework for heattransfer.Atthis point, soluthe study of fluidtions were based on approximatemethods, since the governing mathematicalmotionequations weretoo complex to exactly solve.In combustion,Y.B.Zel'dovitch,aRussian scientist,was able toformulate solutions for diffusion flames by innova-tive approximatemathematicaltechniques.Althoughbegun inthe1930s,the sub-ject of combustion was not developed to a mature state until the 1950s.Today,large computers make it possibleto examine manyfacets of the subject but issuesofturbulence,chemicalkinetics,andothersmall-scalephenomena still cannotbecompletely resolvedby computer solutions.The engineer must still rely on intel-lectual insightand approximateformulations.Moreover,onlywhen a thoroughunderstanding of a subject is mastered can simple representations ofcomplex phe-nomena be made.This also allows the transfer of knowledge and its ease of use.The subject of fire needed to build on all of its component disciplines.Thesehad to mature before it was even possible to adequately describe and predict fire.Anotherfactorinfluencing thedevelopmentoffire scienceisthemotivationto study it in thefirst place.We have seen that fire is a drain on the economy,andthere is no direct market incentive for its study.In Japan,the consequences ofearthquakes led to an extremesensitivitytofiresafety and its study.Fire scienceis studiedinschools of architecture in Japan aswell as in other scientific fields.It is endemic in Japanese culture and academicdisciplines.Not surprisingly,thefirst science-basedhandbookon the quantitativedescriptionof firewas published in Japan in theearly1980s.England developed one ofthe mostadvanced scientific laboratoriesforfirestudy in the world (the Fire Research Station, formerly at Borehamwood).Muchof thework in the1960s under the leadership of Dennis Lawson,Philip ThomasandDavidRasbashhasnotbeenfullyappreciatedbecauseitwasneverpublishedin mainstreamfire journals.But it is recognized that thefirstgraduate program infire engineering was founded by David Rasbash at the University of Edinburgh,and PhilipThomas has been a main force in disseminating thebenefits of fire sci-encethroughouttheworld,Many of the pioneers of fire science came together in a special meeting inWashington,D.C.on November 9 and 10, 1959,for"The Use of Models in FireResearch."Walter Berl,the conference organizer,commented,"The intimate inter-playbetweenaerodynamics,heattransfer,and chemical reaction ratesmakesthestudy of fires the intriguing problem it is."1o Scientists who have achieved promi-nence outside the field of fire have elected to study firebecause of its challengeand theprospectof itsbenefitsto society

Chapter 1 The Evolution of Fire science heat transfer the transport of energy from a high- to low-temperature object fluid mechanics the study of fluid motion entist, who brought a unification and clarity to the subject that is still appreciated today. Heat transfer also had its roots in the early 1800s. Joseph Fourier, a general in Napolean's army, formulated the law of heat conduction that forms the theoretical basis of the field. But heat transfer in fluids had to await the development of modern fluid mechanics in the late 1800s when 0. Reynold's pioneering work on turbulent flow laid the basis for engineering analysis. In the 1900s, Theodore von Karman and others advanced the subject of aerodynamics, which paved the way for a more complete framework for heat transfer. At this point, solutions were based on approximate methods, since the governing mathematical equations were too complex to exactly solve. In combustion, Y. B. Zel'dovitch, a Russian scientist, was able to formulate solutions for diffusion flames by innovative approximate mathematical techniques. Although begun in the 1930s, the subject of combustion was not developed to a mature state until the 1950s. Today, large computers make it possible to examine many facets of the subject but issues of turbulence, chemical kinetics, and other small-scale phenomena still cannot be completely resolved by computer solutions. The engineer must still rely on intellectual insight and approximate formulations. Moreover, only when a thorough understanding of a subject is mastered can simple representations of complex phenomena be made. This also allows the transfer of knowledge and its ease of use. The subject of fire needed to build on all of its component disciplines. These had to mature before it was even possible to adequately describe and predict fire. Another factor influencing the development of fire science is the motivation to study it in the first place. We have seen that fire is a drain on the economy, and there is no direct market incentive for its study. In Japan, the consequences of earthquakes led to an extreme sensitivity to fire safety and its study. Fire science is studied in schools of architecture in Japan as well as in other scientific fields. It is endemic in Japanese culture and academic disciplines. Not surprisingly, the first science-based handbook on the quantitative description of fire was published in Japan in the early 1980s. England developed one of the most advanced scientific laboratories for fire study in the world (the Fire Research Station, formerly at Borehamwood). Much of the work in the 1960s under the leadership of Dennis Lawson, Philip Thomas, and David Rasbash has not been fully appreciated because it was never published in mainstream fire journals. But it is recognized that the first graduate program in fire engineering was founded by David Rasbash at the University of Edinburgh, and Philip Thomas has been a main force in disseminating the benefits of fire science throughout the world. Many of the pioneers of fire science came together in a special meeting in Washington, D.C. on November 9 and 10, 1959, for "The Use of Models in Fire Research." Walter Berl, the conference organizer, commented, "The intimate interplay between aerodynamics, heat transfer, and chemical reaction rates makes the study of fires the intriguing problem it is." 10 Scientists who have achieved prominence outside the field of fire have elected to study fire because of its challenge and the prospect of its benefits to society

Chapter1TheEvolution of FireScienceIn the United States, one of the earliest scientists of fire was Hoyt Hottel ofM.I.T.He began thestudy of fire before World War I, but was diverted to studytheeffects offire from weapons during thewar.Later,he and Emmons of HarvardUniversity pursued fundamental research in fire and lobbied for governmentresearchfunding.Such research support wasrealized in the early1970sby expan-sions of fire research at Factory Mutual Research Corporation and at the NationalInstitute of Standards and Technology (formerly the National Bureau of Stan-dards).It was made possible bytargeted funding for fire research by the NationalScienceFoundationandthroughtheNational FirePreventionand ControlActof1974.The fruits of that research effort in the 1970s helped to promote, develop,and catalyzethe disconnected efforts of fireresearch throughoutthe world.Although U.S.funding for basic research in fire has since decreased, the world-wideactivity is expanding in its communication links,andthere is a healthyexchange ofknowledge in this small field.For example,proceedings of the sym-posia sponsored by the International Association forFire Safety Sciencehelp tomaintain international exchange in fire research. It is this synthesis offire researchthat makes possiblethis book.The SFPE Handbook of FireProtectionEngineer-inglideveloped by the Societyof Fire Protection Engineers (SFPE)is agood illustration of the current knowledge base of fire science compiled by experts amongthedisciplines offire.VISUALIZATION OFFIREPHENOMENAINOTEItiscrucial tohaveavisualconceptoffirephenomenabeforeonecan establishaframework for study.Many effects are seen (or can be seen if planned) during theThe shapeofa flame isprogression of fire and its related smoke movement.These must be categorized ifinfluenced by the fluidwe are to learn.The shape of a flame is influenced by the fluid flow induced byflow induced by thethe flame itself.Thenature of smoke movement in buildings can takemanyforms.flame itself.Such visualization musttakeplacein the laboratoryforsystematicstudy,butfirefightersandothersmustbeabletarticulatetheirobservationstoscientiststopromote their study.The scientistallowthesizeofhislaboratorytolimitthescopeorrelevanceof hisobservationsinfirephenomena.However,small-scalestudies can be very relevant. We all appreciate the role of wind tunnels in thedesign of aircraft and in improving the aerodynamics of motor vehicles.TheWright brothers had a wind tunnel at their disposal. Such scale modeling tech-niques pervademany fields of study;fire is not excluded.Physical scale modelsbasedonthelawsofsciencecanhelptodesign aircraft,ships,oceanictidalbasins,concert halls,and even analyze vehicle crash dynamics.Processes in fire can alsobe reasonably represented by scalemodels.Manyoftheformulas wewill studyinthis book haveresulted from scaling techniques using laboratory-size systemsFigure1-5isa schematic illustration of phenomena arising in a roomfire.Therecognitionof these and otherphenomena helped to establishaframeworkfor the"modeling"of compartmentfires.Figures 1-6 and 1-7,respectively,show thedynamics of smoke movement and fluid flow in a corridor subjected to a room

_ ._ _ c_h_ap_te_r_1_Th_e_E_vo_1ut_io_n_of_F_ir_e_sc_ie_nc_e ■ NOTE The shape of a flame is influenced by the fluid flow induced by the flame itself. In the United States, one of the earliest scientists of fire was Hoyt Hottel of M.I.T. He began the study of fire before World War II, but was diverted to study the effects of fire from weapons during the war. Later, he and Emmons of Harvard University pursued fundamental research in fire and lobbied for government research funding. Such research support was realized in the early 1970s by expansions of fire research at Factory Mutual Research Corporation and at the National Institute of Standards and Technology (formerly the National Bureau of Standards). It was made possible by targeted funding for fire research by the National Science Foundation and through the National Fire Prevention and Control Act of 1974. The fruits of that research effort in the 1970s helped to promote, develop, and catalyze the disconnected efforts of fire research throughout the world. Although U.S. funding for basic research in fire has since decreased, the worldwide activity is expanding in its communication links, and there is a healthy exchange of knowledge in this small field. For example, proceedings of the symposia sponsored by the International Association for Fire Safety Science help to maintain international exchange in fire research. It is this synthesis of fire research that makes possible this book. The SFPE Handbook of Fire Protection Engineering11 developed by the Society of Fire Protection Engineers (SFPE) is a good illustration of the current knowledge base of fire science compiled by experts among the disciplines of fire. VISUALIZATION OF FIRE PHENOMENA It is crucial to have a visual concept of fire phenomena before one can establish a framework for study. Many effects are seen (or can be seen if planned) during the progression of fire and its related smoke movement. These must be categorized if we are to learn. The shape of a flame is influenced by the fluid flow induced by the flame itself. The nature of smoke movement in buildings can take many forms. Such visualization must take place in the laboratory for systematic study, but firefighters and others must be able to articulate their observations to scientists to promote their study. The scientist cannot allow the size of his laboratory to limit the scope or relevance of his observations in fire phenomena. However, small-scale studies can be very relevant. We all appreciate the role of wind tunnels in the design of aircraft and in improving the aerodynamics of motor vehicles. The Wright brothers had a wind tunnel at their disposal. Such scale modeling techniques pervade many fields of study; fire is not excluded. Physical scale models based on the laws of science can help to design aircraft, ships, oceanic tidal basins, concert halls, and even analyze vehicle crash dynamics. Processes in fire can also be reasonably represented by scale models. Many of the formulas we will study in this book have resulted from scaling techniques using laboratory-size systems. Figure 1-5 is a schematic illustration of phenomena arising in a room fire. The recognition of these and other phenomena helped to establish a framework for the "modeling" of compartment fires. Figures 1-6 and 1-7, respectively, show the dynamics of smoke movement and fluid flow in a corridor subjected to a room