Characteristics of steady burning over inclined polymethyl methacrylate surface in different pressure environments

This paper aims to examine the characteristics of steady burning of inclined polymethyl methacrylate (PMMA) slabs under different ambient pressures. A sequence of experiments concerning steady burning intensity and combustion efficiency of the sample were conducted under both normal pressure (Hefei: altitude 30 m, 100 kPa) and reduced pressure (Lhasa: altitude 3650 m, 64 kPa). An in situ calorimeter based on oxygen consumption method was employed to measure the heat release rate of materials. A semi-theoretical model based on convective heat feedback from the flame was proposed and fitted well with laminar-dominated flame over the inclined PMMA surface. The critical maximum side length of sample for laminar-dominated flame in Hefei is lower than Lhasa. The trend of combustion efficiency with increasing inclination angle shows a great difference under different pressure environments.