THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

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The maximum excess temperature of fire-induced smoke flow beneath an unconfined ceiling at high altitude

ABSTRACT
Conventional correlations for the maximum temperature under a ceiling were mainly developed based on the experimental results at atmospheric pressure. For high-altitude environment with lower ambient pressure, their feasibility needs to be reexamined. In this paper, a sequence of pool fires with different dimensions and fuel types was performed under a horizontal unconfined ceiling to measure the maximum excess temperature in a high-altitude city, Lhasa (3650 m/ 64.3 kPa). The results show that the maximum smoke temperatures beneath the ceiling at high altitude are significant higher than the predicted values by Alpert's model. Considering the effects of ambient pressure and entrainment coefficient, a new theoretical model for predicting the maximum excess temperature was proposed based on the ideal plume assumption. The current results together with the data in the literature which conform with Alpert's model successfully converge by employing the proposed correlation.
KEYWORDS
PAPER SUBMITTED: 2017-09-26
PAPER REVISED: 2018-02-15
PAPER ACCEPTED: 2018-02-19
PUBLISHED ONLINE: 2018-03-04
DOI REFERENCE: https://doi.org/10.2298/TSCI170926075L
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