As a new type of flexible smart material, ionic polymer-metal composite (IPMC) has the advantages of being lightweight and having fast responses, good flexibility, and large deformation ranges. However, IPMC has the disadvantages of a small driving force and short lifespan. Based on this, this paper firstly analyzes the driving mechanism of IPMC. Then, it focuses on the current preparation technology of IPMC from the aspects of electroless plating and mechanical plating. The advantages and disadvantages of various preparation methods are analyzed. Due to the special driving mechanism of IPMC, there is a problem of short non-aqueous working time. Therefore, the modification research of IPMC is reviewed from the aspects of the basement membrane, working medium, and electrode materials. Finally, the current challenges and future development prospects of IPMC are discussed.

The vortex structure is a typically coherent structure. The influence of hydrofoil jets with different chordal positions on the vortex structure in the hydrofoil flow field is investigated to improve the suppression mechanism of cavitation by jet hydrofoils. The investigation is based on a vortex identification method and the chordal position with the best suppression effect on the large-scale vortex on the hydrofoil surface is explored. In addition, the dynamics of the vortex structure in different cavitation states are analyzed by means of vortex transport equations based on the optimal chordwise position. The results show that the U-shaped vortex is the main morphology of the hydrofoil surface bubble shedding; the results show that the U-shaped vortex is the main form of cavitation shedding on the hydrofoil surface; compared with the original hydrofoil and other jet positions, the shedding of large-scale vortex structure can be suppressed better when the jet is located at 0.6c; the dominant vorticity transport terms are different in various cavitation stages. In the primary cavitation stage, the vorticity dilatation term is dominant. In contrast, during the development, maturation, and shedding phases, the vortex stretching term dominates, reducing the pressure gradient in the hydrofoil flow field and suppressing the strength of the return jet.

The characteristics of the material transported by the two-vane pump can cause the impeller to wear out, leading to a deterioration in hydraulic efficiency. Appropriately, the research goal of this paper is to consolidate the anti-wear performance of the two-vane pump conveying a solid-liquid two-phase flow. Based on the bionic principle and the anti-wear structure of blood clams, the circular non-smooth structure adapted from blood clams is arranged in the wear-prone area. Through numerical simulation, we compare the main indexes of the pump: the head, the pressure distribution, the vortex pressures, and the average wear rate, to reveal the wear resistance mechanism of circular non-smooth structures. The results illustrate that the use of a circular non-smooth structure does not modify the external characteristics of the pump; the pressure distribution inside the impeller is similarly consistent, and the vortex pressures are all approximately the same. The average wear rate is higher when the diameter of the circular non-smooth structure is either 0.25 mm or 0.30 mm, and the simulation results are poor. At a diameter of 0.20 mm, the average wear rate of circular non-smooth blades is at its lowest point. The circular non-smooth surface structure causes impurities to be “caught” by the vortex zone and not freely struck against the wall, resulting in the particles migrating away from the blade.

In order to improve the anti-wear performance of a double-vane self-priming centrifugal pump during two-phase flow transfer, the construction of a streamline groove structure at the outlet end of the suction side of the vane, based on the bionic principle, is proposed. Different pump characteristics are analysed to investigate the effect of different bionic groove spacing on the resistance to particle wear and the mechanism of improvement of the bionic grooves. The results show that the effect of the bionic blades on the hydraulic characteristics of the pump is within the allowable error (±1.4%). The circular groove structure with different spacing produces a difference in the pressure distribution on the blade. At the same particle concentration, with the increase in the groove spacing distance, the average wear of the blades first decreases and then increases; the average wear rate at the spacing of 7 mm is the smallest. At a particle concentration of 90 kg/m³, the average wear rate at a groove spacing of 7 mm is ~0.63 × 10⁻⁴ kg/s∙m², and the wear area is mainly found in the middle of the blade. The reason why the bionic blade improves the anti-wear performance of the pump is due to the reverse vortex zone in the groove, which changes the particle trajectory and collision frequency. The bionic grooves with a diameter of 2 mm and a spacing of 7 mm significantly reduce the average wear rate of the pump at different particle concentrations, while maintaining hydraulic performance.

In order to improve the sealing performance of a sealing ring in order to improve the efficiency of the centrifugal pump, based on the bionics principle, a calculation model for the bionic groove surface sealing ring structure of the centrifugal pump is established, based on the Realizable k-ε turbulence model. The external characteristics, internal flow field distribution and leakage characteristics of centrifugal pumps with different bionic groove surface structures and groove diameters are analyzed, and the influence of bionic surface structure on the sealing performance of the centrifugal pump sealing ring is studied. The results show that the bionic groove structure has a certain promoting effect on the external characteristics of the pump; a sealing ring with a circular groove structure can improve the efficiency, greatly reduce the leakage, and has better sealing performance, which are important influences on the performance and stability of the centrifugal pump. Among the three different diameters of the circular groove, the optimal groove diameter of the surface structure is 0.2 mm, where leakage is the least, volume efficiency is the largest, and sealing performance is the best.