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

• Published in: Science China. Technological sciences Vol. 58; no. 6; pp. 1072 - 1083
• Main Authors: Zheng, Zhiying, Li, Fengchen, Li, Qian, Kulagin, Vladimir A.
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01-06-2015
• Subjects: Engineering; 优化再设计; 数值模拟; 数值研究; 旋转蒸发器; 楔形; 特征; 超空泡; 面对称; CFD numerical simulation; desalination; planar symmetric wedge-shaped cavitators; rotational supercavitating evaporator
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-015-5827-y

With the application of supercavitation effect, a novel device named rotational supercavitating evaporator（RSCE） was recently designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization and then design three-dimensional blades, numerical simulations are conducted on the supercavitating flows（with cavitation number ranging from 0.055 to 0.315） around two-dimensional planar symmetric wedge-shaped cavitators with different wedge angles varied from 10 to 180 degrees. Proper numerical method for simulating supercavitating flows around planar symmetric cavitator is established, and assessment of k-ε-v2 -f turbulence model in simulating cavitating flows is conducted. It shows that the size of computational domain would affect the simulation result. Empirical formulae for supercavity dimensions about cavitation number at different wedge angles are obtained, which are of significant importance in the subsequent design of three-dimensional blade. The characteristics of resistance at different wedge angles are discussed, which, together with the characteristics of supercavity dimensions, play important roles in the optimal design of RSCE.