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The term ‘heat flux’ is used ambiguously. Clear definitions are needed on how to express thermal exposure
Author(s) -
Wickström Ulf
Publication year - 2016
Publication title -
fire and materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.482
H-Index - 58
eISSN - 1099-1018
pISSN - 0308-0501
DOI - 10.1002/fam.2286
Subject(s) - heat flux , terminology , flux (metallurgy) , term (time) , thermal , boundary (topology) , boundary value problem , high heat , mechanics , environmental science , heat transfer , mechanical engineering , computer science , nuclear engineering , engineering , forensic engineering , thermodynamics , materials science , physics , mathematics , composite material , mathematical analysis , linguistics , philosophy , quantum mechanics , metallurgy
Summary The expression ‘heat flux’ without any qualifier like ‘to a surface at ambient temperature’ as frequently used in fire safety science and engineering literature and standards is ambiguous and misleading. Boundary conditions in fire safety engineering problems cannot be expressed as a given heat flux (or net heat flux), as the heat flux depends on and varies with the exposed surface temperature and thereby the properties of the target body. Therefore, it is important that the terminology is reviewed and that an agreement is reached on how to express thermal exposure in a well‐defined and unambiguous way. A proposal is given on how the boundary conditions can be defined in a consistent way that is applicable to fire resistance and reaction‐to‐fire problems. Copyright © 2014 John Wiley & Sons, Ltd.