Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite ma...Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite material characterized by vertical flame spread and different inside/outside combustion behaviors. In addition, major factors that affect the flame spread outside the building include the combustion characteristics of materials used as well as air flow around a skyscraper. However, since it is highly difficult to analyze and forecast the air flow from a fire engineering viewpoint, an investigation of the flame spread characteristics of exterior walls of a building depends primarily on the combustion characteristics of materials. Hence, this study examined, using ISO 13785-2 testing method, the temperature changes and vertical flame spread behaviors of one of the finishing materials for exterior walls--（generic ＆ fire-resistant） aluminium panels by a real-scale combustion experiment. According to the results of real-scale experiment, the maximum heat temperature of 987.7 ℃ was recorded seven minutes after the fire test was initiated while the fire-resistant aluminium panels showed the maximum heat temperature of 850.2℃ after exposed for approximately 12 min. The vertical flame spread properties put more emphasis on the time required to reach the maximum temperature rather than its magnitude and there was a five minutes difference between the materials.展开更多
Laminar flame speed is one of the most important intrinsic properties of a combustible mixture. Due to its importance, different methods have been developed to measure the laminar flame speed. This paper reviews the c...Laminar flame speed is one of the most important intrinsic properties of a combustible mixture. Due to its importance, different methods have been developed to measure the laminar flame speed. This paper reviews the constant-volume propagating spherical flame method for laminar flame speed measurement. This method can be used to measure laminar flame speed at high pressures and temperatures which are close to engine-relevant conditions. First, the propagating spherical flame method is introduced and the constant-volume method （CVM） and constant- pressure method （CPM） are compared. Then, main groups using the constant-volume propagating spherical flame method are introduced and large discrepancies in laminar flame speeds measured by different groups for the same mixture are identified. The sources of discrepancies in laminar flame speed measured by CVM are discussed and special attention is devoted to the error encountered in data processing. Different correlations among burned mass fraction, pressure, temperature and flame speed, which are used by different researchers to obtain laminar flame speed, are summarized. The performance of these correlations are examined, based on which recommendations are given. Finally, recommendations for future studies on the con- stant-volume propagating spherical flame method for laminar flame speed measurement are presented.展开更多
文摘Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite material characterized by vertical flame spread and different inside/outside combustion behaviors. In addition, major factors that affect the flame spread outside the building include the combustion characteristics of materials used as well as air flow around a skyscraper. However, since it is highly difficult to analyze and forecast the air flow from a fire engineering viewpoint, an investigation of the flame spread characteristics of exterior walls of a building depends primarily on the combustion characteristics of materials. Hence, this study examined, using ISO 13785-2 testing method, the temperature changes and vertical flame spread behaviors of one of the finishing materials for exterior walls--（generic ＆ fire-resistant） aluminium panels by a real-scale combustion experiment. According to the results of real-scale experiment, the maximum heat temperature of 987.7 ℃ was recorded seven minutes after the fire test was initiated while the fire-resistant aluminium panels showed the maximum heat temperature of 850.2℃ after exposed for approximately 12 min. The vertical flame spread properties put more emphasis on the time required to reach the maximum temperature rather than its magnitude and there was a five minutes difference between the materials.
基金supported by the National Natural Science Foundation of China(51322602)
文摘Laminar flame speed is one of the most important intrinsic properties of a combustible mixture. Due to its importance, different methods have been developed to measure the laminar flame speed. This paper reviews the constant-volume propagating spherical flame method for laminar flame speed measurement. This method can be used to measure laminar flame speed at high pressures and temperatures which are close to engine-relevant conditions. First, the propagating spherical flame method is introduced and the constant-volume method （CVM） and constant- pressure method （CPM） are compared. Then, main groups using the constant-volume propagating spherical flame method are introduced and large discrepancies in laminar flame speeds measured by different groups for the same mixture are identified. The sources of discrepancies in laminar flame speed measured by CVM are discussed and special attention is devoted to the error encountered in data processing. Different correlations among burned mass fraction, pressure, temperature and flame speed, which are used by different researchers to obtain laminar flame speed, are summarized. The performance of these correlations are examined, based on which recommendations are given. Finally, recommendations for future studies on the con- stant-volume propagating spherical flame method for laminar flame speed measurement are presented.
