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Experimental study on smoke temperature distribution characteristics in corridors of crew cabins
Chinese Journal of Ship Research 2023, 18(6): 119-127
Published: 06 April 2023
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Objective

When a fire occurs in the multi-storey dwelling section of a ship, the temperature distribution pattern during the spread of smoke along corridors and ladder openings is significantly different from that of a building fire. Therefore, it is necessary to fully understand the characteristics of fire smoke in crew cabins.

Methods

An experimental study on the temperature distribution characteristics of fire smoke in single and multi-storey corridors is carried out in a 1︰5 scaled down ship model by changing the size of the heptane oil pool and the states of ladder openings.

Results

In the case of a single-storey spread of fire smoke, the vertical temperature distribution in the corridor shows an obvious thermal stratification phenomenon with a height of over 0.4 m. In the case of a multi-storey spread, the vertical temperature gradient in the corridors is lowered and the thermal stratification height is reduced to 0.2 m or less; the vertical thermal stratification height within the corridors is reduced at corners and turnouts; the smoke temperature continues to decrease during horizontal spreading; and the temperature distribution satisfies the exponential decay law.

Conclusions

The thermal stratification height in a multi-storey corridor is significantly reduced compared with a single-storey spread of fire smoke, and the temperature attenuation coefficient k in the horizontal spread process increases as the size of the fire source increases. The results of this study can provide theoretical support for the fire risk assessment and fire protection design of ships.

Research Article Issue
Buoyancy-driven flow through a ceiling aperture in a corridor: A study on smoke propagation and prevention
Building Simulation 2015, 8(6): 701-709
Published: 06 August 2015
Abstract PDF (1.8 MB) Collect
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Analyzing numerous computational fluid dynamics (CFD) simulations of a two-level corridor model, smoke propagation and prevention were investigated. In all simulations, the fire source was placed inside the lower corridor, which we refer to as the fire corridor. Results show that after smoke flows in through the ceiling aperture, a dangerous environment forms quickly in the upper corridor. The smoke layer in the upper corridor descends nearly to floor level through buoyancy and air flowing in through the doorways. The fire hazard created in the upper level is larger than that of the fire corridor. In regard to fire prevention, the effectiveness of a counter airflow at the ceiling aperture is demonstrated, and critical velocities for counter airflow are derived through CFD simulations. A simple model for predicting this critical velocity is proposed based on the Froude modeling. The critical Froude number initially declines linearly with the dimensionless distance between the fire source and the ceiling aperture, and then stabilizes at 0.38 when this distance is larger than 3.00. This model can be used for coarse design of the counter airflow smoke control system.

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