Radiative ignition of fabrics and assemblies: Experiments and modelling
| Autor: | P. Durbetaki, Phuoc X. Tran |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Numerical Analysis
Materials science Applied Mathematics General Engineering Thermodynamics Computer Science::Other law.invention Ignition system Reaction rate Minimum ignition energy Heat flux law Thermal Radiative transfer Limiting oxygen concentration Physics::Chemical Physics Composite material Pyrolysis |
| Zdroj: | International Journal for Numerical Methods in Engineering. 30:859-873 |
| ISSN: | 1097-0207 0029-5981 |
| DOI: | 10.1002/nme.1620300418 |
| Popis: | Radiative ignition studies wre carried out on vertical 2.54 cm circular fabric pairs, and single fabrics of 2.54 cm diameter and 15.2 × 15.2 cm. These fabrics were exposed to a time invariant radiative heat flux using the Large Ignition test Apparatus (LITA) and the Radiative Ignition Time Apparatus (RITA). A model has been developed which uses a quasi-steady-steady-state approximation for the gas pahse. The transient effects and the thermal interaction between the plne-parallel fabrics are accounted for through the variation of the fabric temperature with time. Ignition is considered to occur when the gas phase pyrolysate reaction rate is equal to the rate of pyrolysis. The predicted ignition times are compared with measured values and they show excellent agreement. Ignition times were found to depend strongly on heat flux, fabric size, interface spacing and oxygen concentration. IN the presence of a back fabric, the ignition time of the front fabrics decreases and this reduction is more pronounced at lower radiative heating intensities. Strong thermal interaction between the fabrics was also observed and it is expected that such interactions are responsible for the reduction of ignition time of the front fabric. No evidence of chemical interaciton has been observed. |
| Databáze: | OpenAIRE |
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