Reduced Pressure Effect on The Centerline Plume Temperatures of Elevated n-Heptane Fires in an Aircraft Cargo Compartment

ABSTRACT

This paper investigates the influence of the reduced pressure on the temperature profile of the weak and strong fire plumes by elevating n-Heptane fires. A series of elevated n-Heptane fire tests were conducted in a full-scale simulated Boeing 737–700 aircraft cargo compartment at 70 kPa, 80 kPa, 90 kPa and 100 kPa. The experimental results show that both the centerline temperature rise and the maximum ceiling temperature rise of weak and strong plumes at reduced pressures can be represented in three-region law similar to McCaffrey plume model. Thereinto, the weak plume temperature increases with the decrease of the atmosphere pressure owing to the low air entrainment, while the strong plume temperature in the continuous flame region decreases at reduced pressure, because the hot thermal flow of the strong plume impinges the ceiling violently causing the more air entrainment. The maximum ceiling temperature at the reduced pressure changes as similar with the centerline temperature driven by strong plumes. By introducing the reduced pressure coefficients, new correlations for predicting the centerline temperature and maximum ceiling temperature induced by weak and strong plumes are proposed with wider application range.

KEYWORDS:

• n-Heptane
• thermal impinging flow
• reduced pressure
• plume temperature profile
• aircraft cargo compartment fires

Highlights

• Temperature profiles of weak/strong thermal n-Heptane flows at various pressures.

• Proposed reduced pressure coefficients for plume temperature empirical equations.

• Modified three-region correlations to predict plume temperature at low pressure.

• Modified correlations of maximum ceiling temperature fit for low pressure.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

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Greek symbols

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Subscript

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was supported by National Natural Science Foundation of China under Grant No. 51806156 and 52076199; Hubei Provincial Key Research and Development Program under Grant No. Science and Technology Department of Hubei Province 2020BCB072; Project of Natural Science Foundation of Hubei Province under Grant No. 2018CFB226.