Eddy Diffusivities for Heat in the Region near the Wall

The eddy diffusivities for heat were measured by the use of a Mach-Zehnder interferometer, and the ratio of eddy diffusivities for heat and momentum in the region close to the wall was predicted by a modified mixing length theory. There was fairly good agreement between the experimental and theoretical results

プラントルスウ マタワ シュミットスウ ガ オオキイ バアイ ノ カンゼン ニ ハッタツシタ ランリュウ リョウイキ ニ オケル ユソウ ゲンショウ

京都大学0048新制・課程博士工学博士甲第1057号工博第239号新制||工||176(附属図書館)UT51-46-B88京都大学大学院工学研究科化学機械学専攻(主査)教授 水科 篤郎, 教授 桐栄 良三, 教授 永田 進治学位規則第5条第1項該当Kyoto UniversityDFA

Mass transfer from hot dry rock to water flowing through a circular fracture

Numerical simulation of heat and mass transfer from hot dry rock to flowing water in a circular fracture was conducted to estimate the concentration of the dissolved silica at the production well. The local mass transfer coefficients between the rock and the fluid, obtained by using the electrochemical method during the laboratory experiments, were used in the calculation. The results of the simulation indicate that the concentration of the silica at the production well increases with increasing distance between the injection and the production wells, increasing fracture diameter and increasing pressure. It decreases with increases in flow rate and porosity in the fracture. The concentration of silica at the production well first increases and then decreases with increasing initial rock temperature due to the decrease in the solubility of silica at high temperatures. Finally, the mass transfer by forced convection of flowing water plays an important role in the variation in the concentration of silica in water, and the assumption that the concentration of dissolved silica is equal to that at the fracture surface is not valid for estimation of the concentration at the production well