摘要:

AbstractWhen a specimen is testd for its heat release rate (HRR) behaviour using a bench‐scale such as ISO 5660 or equivalent, one very important test condition is not pre‐standaridized and must be set: the heat flux to be imposed on the specimen by the heater. The heat flux cannot be ligitimately standardized, since the value appropriately to be used will differ according to purpose or application. The present paper sets forth the considerations which should govern the correct choice of heat flux. A discussion is given of minimum ignitiability level; statistical variability at low heat fluxes; the ranges of heat fluxes associated with small actual ignition sources; the heat fluxes associated with fires away from the ignition sources, all the way up to fully‐involved room fires; the application of the product; and the needs associated with mathematical modeling of room fires. Correlational approaches are also illustrated and contrasted to physics‐based ones. Finally, the empirical nature of the present situation is emphasized. Judged from first principles, it would appear that successful prediction of room fire results from bench‐scale test data would require both the testing at a large number of different heat fluxes and the use of algorithms to permit time‐dependent interpolation. Such algorithms have been proposed; however, some very successful predictions are noted with much simpler

ISSN:0308-0501    

DOI:10.1002/fam.810190602

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA comparison is presented of cone calorimeter heat release data between fire retardant treated and untreated wood products. The test results show significant differences between these two groups. The parameters included in the comparison are time to ignition, rate of heat release (peak and average values) and total heat release. The wood‐based products were also tested in different small‐scale national standard fire tests and in the full‐scale room fire test. Fire retardant wood products achieve an improved classification both in present national systems and in possible new systems based on the cone calorimeter and the room fire

ISSN:0308-0501    

DOI:10.1002/fam.810190603

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper is based upon an actual post‐crash investigation of a high‐performance single‐eingine aircraft that crashed in mountainous terrain resulting in a post‐crah fire. A detailed metallurgical study of the fuel system separations was undertaken to identify which fittings or fuel lines had suffered mechanical damage during the initial impact sequence and which had been damaged by the post‐crash fire or in subsequent handling of the wreckage. This paper discusses some of the basic metallurgical theories used in failure analyses of aluminum alloy components involved in post‐crash fire studies. Its primary purpose is to discriminate between thermal effects of fire and mechanical overload, specifically for fuel system components. Metallurigical characterisitics cause certain specific signatures of ‘witness marks’ in mechanically induced speartions and different features in post‐crash fire separations. Discussed are frequently observed metallurgical sigantures that may be used to evaluate post‐crash, post‐fire damage. Based on the metallurgical evidence and the principles described in this paper, it was obvious that the root cause of damage to these fuel system components was either thermal exposure during the post‐crash fire or breakage after the fire during handling of the wreckage. Therefore, it was concluded that the fuel system components described herein had not been compromised during the inital impact, but rather had released fuel only after the post‐crash fire. These principles can be utilized in similar investigations but it is important to recognize the chaotic nature of seveeere crashes and the wide range of possible damage features that may result. Each investigation must, of necessaity, be based upon both basic principles and an overall assessment of the quality of the evidence as well as the need to resolve what may appear to be conflicting or questionable features

ISSN:0308-0501    

DOI:10.1002/fam.810190604

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractForest fires involve a wide range of unknown variables, e.g. wind flow over complex terrain, atmospheric stability, vegetation burning characteristics, location and fuel type, etc. The main objective of the present work is to incorporate the Rothermel simplified combustible model into a 3D unsteady flow solver appropriated for convective atmospheric flows over complex terrain. The released combustion energy is taken into account in the enthalpy equation. The unsteady byouant plume strongly influences the local wind speed direction and magnitude. A speical interactive coupling procedure was developed that links the calculated location of fire front and fire energy release to the momentum and energy transport for each time step. The general computer algorithm includes several other features such as the effect‐drag of trees on the momentum transport and the consequent modifications in thekand ε turbulence model employed. The results include the prediction of fire development in flat terrain and in a valley and over hills covered by vegetation. A parametric study was conducted to detect the influence of wind speed, vegetation and fuel content on burning area, burning speed and wind speed directi

ISSN:0308-0501    

DOI:10.1002/fam.810190605

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe flame spread process is driven by the net heat flux to the specimen surface, including the flux from the flame itself. This flame flux is important since it comprises a major part of the driving force causing flame fluxes were obtained. The values which are reported do not appear consistent and show more deviation among materials than would be anticipated. The most common fire test used for obtaining engineering data on flame spread (ASTM E 1321) also is not formulated in terms of flame flux as a driving force. This motivated an experimental programme, whereby six materials have been studied using the flame spread geometry of the ASTM E 1321 test, but with additional instrumentation for recording heat fluxes. The flame fluxes obtained experimentally in this study show much less variation among materials than the comparable data from the literature survey.

ISSN:0308-0501    

DOI:10.1002/fam.810190606

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA simultaneous TG‐DSC system (STA‐625) has been used to investigate the suitability of using magnesium hydroxide (MH) as a flame retardant and smoke suppressant in polypropylene (PP) formulations. Several MH/PP formulations were examined at differing concentrations. The presence of MH in the system greatly alters the thermal degradation character of PP. This work forms the first in a series of application notes using various Theometric Scientific Thermal Analysis instrume

ISSN:0308-0501    

DOI:10.1002/fam.810190607

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810190601

出版商:John Wiley&Sons Ltd.    

年代:1995

数据来源: WILEY