Modeling of rotational supercavitating evaporator and the geometrical characteristics of supercavity within

State-of-the-art of R&D on seawater desalination technology

“…Ballester和 Garrido [292] 采用磁场代替ED中 [294] , 经过电磁处理的过热水流经特殊设计的固 定障碍物后, 在其后方形成超空泡, 将从超空泡内抽 取出的蒸汽冷凝得到淡水, 该装置可用于海水淡化 和废/污水净化, 对于TDS为65000 mg/L的原水, 其 能耗为3 kW h/m 3 , 污染物脱除率超过99%. 最近, 本 研 究 小 组 提 出 了 旋 转 超 空 泡 蒸 发 器 (rotational supercavitating evaporator, RSCE)的概念 [4] , 并进行 了初步的设计和研究 [295,296] Fresh water deficit has been an increasingly critical global environmental issue, and seawater desalination is considered as the most effective and promising solution, which promotes the development of different desalination technologies. In order to provide a comprehensive knowledge about the development of desalination technologies, state-of-the-art of research and development on the application of desalination technologies is reviewed in this paper.…”

Numerical study on the characteristics of natural supercavitation by planar symmetric wedge-shaped cavitators for rotational supercavitating evaporator

“…is obtained for the simulation result, which is in good agreement with the theoretical formula by Tulin [9] from an engineering point of view. Supercavity length is a key parameter for the design of three-dimensional blade shape, and it is compared with the arc length at the corresponding radius to determine the thickness of blade's exit edge [2]. In view of the prediction for the natural supercavity length, V2F model is thus testified to be able to meet our needs, and thus is utilized in the following numerical simulations.…”

“…It indicates that the critical rotational speed of the blade in RSCE, at which supercavity has the largest volume (one can refer to Figure 9 in ref. [2]), is possible to be lowered with decreased resistance for the same blade exit edge thickness, or in other words, there could be an optimal wedge angle and rotational speed for the design of blade shape to get a highest desalination efficiency for RSCE. On the other hand, from the viewpoint of reducing resistance, since the pressure drag accounts for most of the total drag, effort should be made to decrease the pressure drag, e.g., by designing streamlined shape of the cavitator.…”

“…For membrane method, rigorous pre-treatment is necessary for the avoidance of fouling formation and low recovery factor. In order to overcome these shortcomings, a novel approach for fresh water acquisition using supercavitation phenomenon was proposed, based on which a device named rotational supercavitating evaporator (RSCE) was designed and fabricated for desalination or purification of polluted water [1][2][3].…”