The term 'heat flux' is used ambiguously. Clear definitions are needed on how to express thermal exposure

摘要

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 (c) 2014 John Wiley & Sons, Ltd.