倉渕隆

"A Study on the Effects of Porosity on Discharge Coefficient in Cross-Ventilated Buildings Based on Wind Tunnel Experiment"
「通風開口部の流量係数に空隙率が及ぼす影響の検討」

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A study was performed on the effects of porosity on discharge coefficient and air flow characteristics under the condition where uniform approaching flow directly faces to and enters the opening by using wind tunnel experiment and CFD analysis. The evaluation was performed on the porosity in the range of 0.4% - 64%. The results of wind tunnel experiment suggest that discharge coefficient increases when porosity is higher. The results of CFD analysis reveal that the contraction of air flow when it passes through the opening is correlated with discharge coefficient, and that discharge coefficient increases when flow contraction does not occur. When porosity increases, the retardment of streamtube does not occur any more in the region upstream of the opening, and this leads to the elimination of flow contraction, hence the increase of discharge coefficient. When we evaluated the limitation of application of local dynamic similarity model on porosity, the effectiveness of the model was confirmed well when porosity was 16% or lower regardless of wind direction, and that the validity of the model was also confirmed under the condition where air flow goes along wall surface before reaching the opening even when porosity was 36% or more.

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東京理科大学工学部建築学科教授。1982年東京大学卒業後，1984年修士課程修了。
1985年から1992年まで東京大学工学部助手。東京大学在職中に，米国，メリーランド州NIST（元NBS）にて客員研究員を兼任。1991年に東京大学にて工学博士取得。東京理科大学には1992年より勤務。
建物内外気流，汚染拡散，換気効率の数値計算，及び風速分布，換気量測定法，換気設備の性能測定法に関する研究を手がける。NIST滞在中には自作の三次元乱流コードを一般公開。現在は多数の換気関連の共同研究や空気調和・衛生工学会にて規準作成を担当。