報告書番号

N11061

タイトル（和文）

火災モデルCFASTによる大規模区画内火災解析（その1）―区画内空気温度評価への適用性検討―

タイトル（英文）

Fire simulation in large compartments with a fire model "CFAST" (part1)-Survey of applicability for analyzing air-temperature profile in compartments-

概要 （図表や脚注は「報告書全文」に掲載しております）

建築物の耐火設計に広く用いられているゾーンモデルCFASTによる大規模区画内での温度解析精度を調べた．特に，解析条件・モデルパラメータの影響に注視した．区画内温度分布および火源の発熱速度の精緻な測定がおこなわれている電共研試験体系を対象に解析を実施した．本解析から，CFASTが天井付近（高温部）の温度の時刻歴を適切に再現する能力を有していることを確認した．ただし，そのためには適切な解析条件の設定が必須となる．すなわち，実験値に相当する境界条件を付加した解析で得られる高温部の温度の時刻歴は実験値とよく一致した．温度解析結果は，解析条件に強く依存した．特に，区画壁面からの放熱量，火源の発熱速度の影響が顕著となった．一方，解析パラメータの影響は小さかった．

概要 （英文）

The basic performance of numerical analysis of air-temperature profiles in large-scale compartments by using a zone model, CFAST (Consolidated model of Fire growth And Smoke Transport), which has been widely applied for fire protection design of buildings is examined. Special attentions are paid to the dependence of the setting boundary conditions and the choosing model parameters. The simulations carried out under the denkyoken-test conditions, in which the air-temperature profiles in compartments and the heat-release rate of a fire have been precisely measured, indicate that the CFAST has a capability to appropriately represent the time-histories of air-temperature in the high air-temperature layer generated in the vicinity of ceiling of the compartment which includes the source of a fire, by applying the proper boundary conditions, i.e., time-histories of air-temperature in the upper (high temperature) layer given by the CFAST agree well with those of observations. The sensitivity analysis in the simulations also reveals that the appropriately setting of the boundary-conditions, especially for the heat-release ratio from a fire and the heat-transfer rate from walls of compartments to ambient air is vital. Contrary to this, the impacts of choosing numerical parameters on the air-temperature analysis are quite small.

報告者

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