Detailed Investigation of Heat Flux Measurements Made in a Standard Propane-Air Fire-Certification Burner Compared to Levels Derived From a Low-Temperature Analog Burner

Abstract

This paper presents detailed heat flux measurements on a flat plate subjected to the ISO2685 [The International Organization for Standardization (ISO), 1992, “Aircraft—Environmental Conditions and Test Procedures for Airborne Equipment—Resistance to Fire in Designated Fire Zones,” ISO2685:1992(E)] standard, propane fueled burner used throughout the industry in aero-engine fire-certification. The authors have developed a custom-built heat transfer gauge to measure the heat flux from the burner under isothermal wall conditions. The heat flux from the standard burner is normally calibrated using either a water-cooled copper tube or a Gardon gauge, each sited at a single position in the flame. There are no reports in the literature of a detailed survey of heat flux distribution for the burner and the results are of considerable interest to engineers involved in fire-certification. The reported measurements constitute the first, detailed distribution of heat flux from the actual burner flame during a fire test. These measurements provided benchmark data which allowed the heat flux distribution from the ISO burner to be compared to levels derived from the low-temperature analog burner developed by the authors. The analog burner uses liquid crystals to measure heat transfer coefficient and adiabatic wall temperature on scale models of engine components and provides key data to facilitate the successful design of components used in fire zones. The objective of this paper is to further validate the low-temperature analog burner technique developed by the authors which simulates the standard large propane-air burner for fire-certification in aero engine.