風除染システム開発研究: 第1報-サーマルマネキンによる強風下の対流熱伝達率分布測定とCFD予測精度の検証

摘要

The main objective of this study was to develop a novel decontamination system based on forced convective flow, e.g. an air shower system. In this paper (Part 1), we report the measurement results of convective heat transfer coefficient of the human body as the first approximation of controlling parameters of mass transfer from skin surfaces. The present study used two types of human models: a seated thermal manikin with 17 body segments whose skin surface temperature was kept at constant for the experiment and a seated Virtual Manikin in accordance with the experimental setup for CFD.rnThe experiments were carried out in wind tunnel with wind speeds ranging from 1.08 to 12.67 m/s. The sensible heat fluxrnfrom the skin surface, the skin surface temperature, the air and surrounding wall surface temperatures were measured as functions of air velocity. Radiative heat transfer analysis based on a numerical simulation was conducted, and then, the sensible heat flux measured by wind tunnel experiments was separated into convective and radiative heat fluxes. Finally, convective heat transfer coefficients (CHTC) for the seated human body segments were estimated as functions of air velocity and turbulent intensity. CFD simulations were also performed out according to the experimental scenarios, and the prediction accuracy of CHTC by CFD using the Virtual Manikin was validated by comparison with experimental data.%NBCテロリズムにおける消防救助活動の一つに被災者の除染がある．対象とする化学剤が気体の場合には乾的除染，液体の場合には水除染を行うことが一般的であるが，両手法共に除染に時間がかかることが予想され，除染所要時間の大幅な短縮が被災者救命・救助のための大きな課題となっている．本研究では，最も多数の被災者が発生することが懸念されるガス体による汚染の場合を想定した，従来の乾的除染に代わる，もしくは併用可能な簡易的かつ即効的な除染として，風除染システムを提案する．特に本報では，風除染システムの基本性能を決定する上で必要となる強制対流場における人体表面からの汚染物質脱離効率評価に向けて，その基礎データとなる人体各部位の対流熱伝達率を風洞実験にて計測した結果を報告する．更に，同条件のCFD解析を実施することで，強風条件下での対流熱伝達率予測に適用可能な乱流モデルの検討を行った結果を併せて報告する．