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.

中文翻译：

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在不同压力环境下聚甲基丙烯酸甲酯倾斜表面的稳定燃烧特性

本文旨在研究倾斜聚甲基丙烯酸甲酯（PMMA）平板在不同环境压力下的稳定燃烧特性。在常压（合肥：海拔30 m，100 kPa）和减压（拉萨：海拔3650 m，64 kPa）下进行了有关样品稳定燃烧强度和燃烧效率的一系列实验。采用基于耗氧法的原位热量计测量材料的放热率。提出了一个基于火焰对流热反馈的半理论模型，并在倾斜的PMMA表面上很好地与层流为主的火焰拟合。合肥的层流型火焰样品的最大临界最大边长低于拉萨。