軒下部に衝突する火炎の熱伝達特性

摘要

A series of model experiment was conducted for evaluating heat transfer to a non-flammable eave during flame impingement. Excess temperature ΔT and incident heat flux to the eave q" were measured under sixteen experimental runs with varying parameters of eave section geometry, burner geometry, installation position of the burner, and fuel supply rate. In order to correlate the maximum excess temperature ΔT_(max)， a reference length scale l was deduced from the governing dimensionless parameter Q~*. Dimensional analysis of thermal structure of the flow showed that the maximum excess temperature ΔT_(max) is expected to be proportional to ((x+H)/L)~0 in the flaming regime, and ((x + h)/L)~(-1) in the non-flaming regime. The agreement with the experimental data was reasonable for all the tested eave sections and burner geometries.%本研究では，模型実験を行って，軒下部に衝突する火炎の熱伝達特性について調べた.この結果，軒下の最大温度上昇ΔT_(max)ならびに入射熱流束q"の減衰特性と，火源設置位置を始点とする無次元距離(x+H)/Lとの間に一定の関係が見られることを確認した.また，ΔT_(max)は，連続火炎領域において一定値をとり，熱気流領域において(x+H)/Lの-1乗に比例して減衰することを解析的に示し，実験結果からもこの妥当性を確認した.