报告题目: |
Radiation Blockage |
报告人: |
John L. de Ris |
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Principal Research Scientist and Asst. Vice President, FM Global
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报告时间: |
2007-09-07 08:30 |
报告地点: |
热能工程系系馆报告厅 |
主办单位: |
热能工程系 |
简介: |
Radiation blockage occurs when hot flame gases encounter a cold surface. The cooling near the surface creates a dense intervening layer of soot and gases that partially block radiation from reaching the surface. The effect is considerable and needs to be included when calculating flame heat transfer in fire growth models. It is further enhanced by mass transfer of pyrolysis gases leaving a burning fuel surface. Measurements of radiation blockage are available in the literature for both wall fires and pool fires. In the present study, we measure the blockage of external radiation for small 9.8 cm diameter pool fires burning PMMA, POM and PVC in different oxygen ambients. The measurements are explained by a one-dimensional model of a diffusion flame including the effects of soot formation, oxidation and radiation. |
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