Numerical analysis of hydrodynamic characteristics of rotational cavitator with improved wedge-shaped blade

Abstract

ObjectivesA rotational cavitator generates supercavitation through the high-speed rotation of its blades in water to meet the practical application requirements of various projects. Therefore, it is necessary to optimize the blade profile in order to improve the working performance, and investigate the influence of the improvement of the blade profile on the hydrodynamic characteristics of the cavitator. MethodsFirst, the original wedge-shaped blade is modified, and 3D geometric models of the cavitator before and after the modification are established. Numerical simulations are then carried out of the natural cavitation generated by two cavitators at different rotational speeds. Finally, the hydrodynamic characteristics of the two cavitators are compared and analyzed according to the calculation results. ResultsThe results show that with the original blade profile, the cavity is only generated by the trailing edge, but with the improved blade profile, the cavity can be also generated by the secondary leading edge, and the two cavities are gradually connected with increasing rotational speed. Therefore, the rotational cavitator with the improved blade profile produces a larger cavity and stronger natural cavitation. In addition, with the improved blade profile, the cavitation effect is relatively stronger at the blade root, while with the original blade profile, it is stronger at the blade tip. The cavity generated by the cavitator with the improved blade profile at higher rotational speed touches the surrounding wall of the device, resulting in a linear change in the shape of the cavity tail along the radius. ConclusionsThe results of this study can provide important references for the design and application of rotational cavitators.

Keywords

• rotational cavitator
• hydrodynamic characteristics
• improved blade profile
• natural cavitation
• numerical simulation