Investigation of enclosure effect of pressure chamber on the burning behavior of a hydrocarbon fuel

Although pressure chambers have been extensively employed to examine the pressure effect on fire behaviors at high altitudes, the results have not been carefully compared with that obtained by field tests for verification. In this paper, both the field tests at high altitude and chamber tests were performed to investigate whether the experimental conditions at high altitude can be faithfully replicated in a low pressure chamber and the limitations or restrictions on the use of the chamber in experimental study of fire behavior at high altitude. The n-heptane pool fires with different sizes were performed in current study. The differences in the burning intensity, flame envelop and axial temperature distribution were analyzed. It was found that only for 6~12 cm pool dimensions, the burning intensity in quasi-steady stage for chamber test can well simulate that for corresponding filed test. The difference in flame envelop appears for all the configurations, exhibiting a larger slenderness for chamber tests. The axial temperature distribution in quasi-steady stage can be well correlated with the classical theory of fire plume involving the pressure effect, while the exception of the 14 cm pool fires shows apparent distinction for field and chamber tests in plume region.