貯水池における連続式空気揚水筒の揚水性能に関する実地調査実験（寸法の異なる実機を用いた取水口近傍および浅層の水流計測）

• Published in: Transactions of the JSME (in Japanese) Vol. 91; no. 943; p. 24-00113
• Main Authors: 中田, 亮生, 野本, 真広, 山岸, 真孝, 中村, 淳一, 早藤, 大輔
• Format: Journal Article
• Language: Japanese
• Published: 一般社団法人 日本機械学会 2025; The Japan Society of Mechanical Engineers
• Subjects: Air-lifting tower; Bubble plume; Field experiment; Reservoir; Water circulation
• ISSN: 2187-9761
• DOI: 10.1299/transjsme.24-00113

To enhance the water quality in stratified reservoirs in summer, a novel air-lifting tower for destratifying water has been deployed since the 2010s in Japan. Compared to conventional water mixing systems that intermittently diffuse air into water bodies to induce water circulation, this air-lifting tower is equipped with nozzles that diffuse air continuously. Simulations using the newly developed system have shown that it is more efficient than conventional systems for increasing the flow rate of water. However, despite the potential benefits of the new system, empirical evaluations are scarce because of limited implementation in reservoirs. Here we present the results of field experiments designed to evaluate the performance of new air-lifting towers that were installed in 2012 as upgrades to conventional air-lifting systems in Yamaguchi Regulating Reservoir in Fukuoka Prefecture. The experiment utilized four air-lifting towers with different diameters (0.5 m, 1.0 m) and lengths (4.0 m, 8.0 m), and water flow velocity was measured at their bottom intakes and near the water surface where the emitted bubble plumes ascend. The data facilitated an estimation of the volume of water flowing into the bottom intakes and rising up to the reservoir surface. Finally, the data were compared with predictions of a previous study, and it was found that they generally corroborated each other.