2010 年 75 巻 4 号 p. 270-276
In this lecture, I present historical positioning of Darcy's Law in fluid mechanics. The classification of fluid flows is proposed by applicability of two common equations; Bernoulli's equation and Darcy's law/Darcy-Weisbach equation. In these equations, pressure has a completely different meaning with conservation or loss. The sketches of separated turbulent flow were left by Leonardo da Vinci in the renaissance period. This kind of the flow observation has played a very important function to develop the fluid mechanics. I also introduce my original visualization photos on the separated turbulent flows. The Darcy's law has been the basic equation in reservoir engineering, however it includes extremely complicate micro flow structure because of mixing of internal and external flows in porous media. As one of interesting examples, visualization photos of SAGD method for producing bitumen from in-situ oil sand layers are presented to compare ours and Dr. Butler's results by scaled models. Finally, I introduce the technical problems of “Biogas” and “Vertical Veges. Garden” observed at slums in Nairobi, Kenya as one of actions related to the project “Education for Sustainable Development in Africa.” These may stimulate young researchers and engineers to make challenge on new visualizations and the sustainable development.