Numerical study on morphological characteristics of rotational natural supercavitation by rotational supercavitating evaporator with optimized blade shape
- 5 Downloads
Based on supercavitation effect, a novel device named Rotational Supercavitating Evaporator (RSCE) has been designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization, the blade shapes with different sizes are designed by utilizing the improved calculation method for the blade shape and the validated empirical formulae obtained by previous two-dimensional numerical simulations, from which the optimized blade shape with the wedge angle of 45º and design speed of 5000 r/min is selected. The estimation method for the desalination performance parameters is established to validate the feasibility of the utilization of the results obtained by two-dimensional numerical simulations in the design of three-dimensional blade shape. Three-dimensional numerical simulations are then conducted on the supercavitating flows around the rotational cavitator with the optimized blade shape under different rotational speeds to obtain the morphological characteristics of rotational natural supercavitation. The results show that the profile of the supercavity tail is concaved toward the inside of the supercavity due to the re-entrant jet. The empirical formulae of supercavity size with account of rotation are fitted, in which the exponents deviate from those obtained by previous two-dimensional numerical simulations. The influences of rotation on the morphological characteristics are analyzed from the perspectives of the tip and hub vortices and the interaction between the supercavity tail and the blade. Further numerical simulation on the supercavitating flow around the rotational cavitator made up by the blades with uniform thickness of exit edge illustrate that the morphological characteristics are also affected by the blade shape.
Key wordsRotational natural supercavitation morphological characteristics blade shape CFD numerical simulation rotational supercavitating evaporator
Unable to display preview. Download preview PDF.
- Likhachev D. S. Study on the hydrodynamic characteristics of rotational supercavitating evaporator [D]. Doctoral Thesis, Harbin, China: Harbin Institute of Technology, 2013.Google Scholar
- Rudenko B. How to make up water resources [J/OL], Journal of Science & Life, 2007, 12, Available from: www.nkj.ru/archive/articles/12366/ (in Russian).Google Scholar
- Langenecker B., Zeilinger C. E. Method and apparatus for desalination of seawater [P]. U.S. Patent 7770830, 2010.Google Scholar
- Langenecker B., Zeilinger C. E. Method for desalination of seawater [P]. U.S. Patent 8021557, 2011.Google Scholar
- Crum L. A., Skinner M., Zeilinger S. A method for desalination and water remediation by hydrodynamic cavitation [C]. Proceedings of Meetings on Acoustics. Acoustical Society of America, Montreal, Canada, 2013, 19(1): 075028.Google Scholar
- Zhang L., Dong H., Wang X. Temperature Response in the Process of Ultrasonic Seawater Desalination [C]. 2011 Asia–Pacific Power and Energy Engineering Conference (APPEEC), IEEE, Wuhan, China, 2011.Google Scholar
- Hong L. Y., Gao M. Y., Zhang J. Y. et al. Research and design of ultrasonic device for seawater desalination [J]. Physics and Engineering, 2014, 24(2): 56–59(in Chinese).Google Scholar
- Franc J. P., Michel J. M. Fundamentals of cavitation [M]. New York, USA: Springer science & Business media, 2006, 111–118.Google Scholar
- IAPWS. Release on the IAPW. Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use [C]. Meeting of the International Association for the Properties of Water and Steam (IAPWS), Fredericia, Denmark, 1996.Google Scholar
- IAPWS. Revise. Release on the IAPS Formulation 1985 for the Viscosity of Ordinary Water Substance[C]. Meeting of the International Association for the Properties of Water and Steam (IAPWS), Vejle, Denmark, 2003.Google Scholar
- Schnerr G. H., Sauer J. Physical and numerical modeling of unsteady cavitation dynamics [C]. Fourth International Conference on Multiphase Flow, New Orleans, USA, 2001.Google Scholar