Experimental study on flame height and temperature profile of buoyant window spill plume from an under-ventilated compartment fire

Self Cite

Abstract. This paper presents an investigation of the side wall effects on facade flames ejected from the opening (such as a window) of an under-ventilated room fire. Experiments are carried out in a reduced-scale experimental setup, consisting of a cubic fire compartment having an opening with a vertical facade wall and two side walls normal to the façade wall. By changing the distance of the two side walls, the facade flame heights for different opening conditions (width, height) are recorded by a CCD camera. It is found that as the distance of the two side walls decreases the behavior the flame height can be distinguished into two regimes characterized by the dimensionless excess heat release rate,Q * ex , outside the opening: (a) for the "wall fire" (Q * ex ≤ 1.3), the flame height is shown to change little with decrease of side wall distance as the dominant entrainment is from the front direction (normal to the facade wall) independent of the side wall distances; (b) for the "axis-symmetrical fire" (Q * ex > 1.3), the flame height increases significantly with a decrease in side wall distance as both the entrainment from the two side directions (parallel to the facade wall) and that from the front direction (normal to the facade wall) together apply. A global physically based non-dimensional factor K is then brought forward based on the side wall constraint effect on the facade flame entrainment to characterize the side wall effect on the flame height, by accounting for the dimensionless excess heat release rate, the characteristic length scales of the opening as well as the side wall separation distance. The experimental data for different opening dimensions and side wall distances collapse by using this global non-dimensional factor.

Section: Resultsmentioning

confidence: 99%

“…The facade flame height is a key parameter in fire spread to the adjacent upper floors, as a result of the radiation and convection of the flames on the facade. Many works [1][2][3][4][5][6][7][8][9][10][11] have been reported in the literatures on this parameter.…”

Section: Introductionmentioning

confidence: 99%

Effects of side walls on facade flame entrainment and flame height from opening in compartment fires

Tang

et al. 2013

Self Cite

“…Many authors have already studied compartment fire with external flames for non-combustible façades [2][3][4] and also combustible façades [5,6]. Studies on non-combustible façade allow to describe flames (flame depth, flame height, thermal actions, etc.)…”

Section: Contextmentioning

confidence: 99%

Experimental study on vertical fire spread along a wooden façade

Duny

Dhima

Garo

et al. 2016

The main purpose of these tests is to get some information on fire spread along a combustible façade in order to assess the ability of numerical codes [1] to simulate flame propagation. Many authors have already studied compartment fire with external flames for non-combustible façades [2][3][4] and also combustible façades [5,6]. Studies on non-combustible façade allow to describe flames (flame depth, flame height, thermal actions, etc.) and to explain the influence of geometrical parameters (opening dimensions, "U" configuration, etc.) on flame shape and flame behaviour. These studies highlight the importance of some of these parameters on vertical spread and correlations are issued from these experimental studies. If many researches on combustible façades exist, it is difficult to find academic configurations with a large instrumentation and generally, these studies focus on a facade system involving complex combustible materials (insulation or composite). That's why it was decided to perform some large scale tests to study fire spread along a vertical wood wall. EXPERIMENTAL SET-UPA principle drawing of the experimental set-up is presented in Fig. 1. The fire room is made of lightweight concrete. As a façade, a fire resistant board is set on a steel frame structure. The total area of the façade is 2.5 m × 4.9 m. The compartment is 1.5 m on a side and 1.15 m high. One side of the compartment is completely open on the façade in order to ensure well-ventilated condition inside the compartment. This test rig is really similar to the British standard façade test which is a real fire propagation test. But in the present test there is no side wall along the façade. As you can see in Table 1, three different tests are carried out. The first test is made without any combustible cladding on the calcium silicate board in order to measure the temperature and the calorific on inert façade. In the second and third tests a cladding of 18 mm thick plywood is mounted directly onto the calcium silicate board, i.e. no ventilation cavity behind plywood. In these two tests, two different type of wood are used, respectively Birch wood and Okoumé (African wood), in order to observe the influence of the essence of the wood on flame propagation and on calorific values. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

“…A lot of work has been carried out to investigate the window-ejected flame and plume upon the exterior walls above the opening [4][5][6][7][8]. Correlations were also developed to characterize flame heights, plume temperatures and heat fluxes upon the facade based on a large amount of small-scale tests [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…Correlations were also developed to characterize flame heights, plume temperatures and heat fluxes upon the facade based on a large amount of small-scale tests [4][5][6]. Although some full scale tests were also carried out [7,8], the attention of effects of plume temperatures and heat fluxes to the glass curtain walls on the upper floors were not well received.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of window-ejected flame and plume on glass curtain walls

Lei

2016

Abstract. This research presents an experimental study to investigate the performance of glass curtain walls exposed to exterior flame and plume ejected from windows. A test facility with 3-storey in height was constructed using steel frame to perform full-scale tests. Ventilation-controlled fire scenarios were designed to generate exterior flame and plume ejected from the burning room through a window opening. To characterize potential threats from window-ejected flame and plume to the glass curtain walls of upper floors, temperature, heat flux and air velocity at different heights above the opening upon curtain walls were measured during each test. The effects of window aspect ratio, horizontal projection were studied. It was found that the window with large aspect ratio provided more severe threat to the curtain walls on upper floors. A horizontal projection of 0.5m in depth was able to protect the glass on the upper floor from breaking.