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With the development of science and technology, the development of underwater vehicles with many advantages such as low energy consumption, low noise, high propulsion efficiency and high mobility, and the exploration is the direction of science and technology, and also becomes a hot research field. This paper introduces the status of researches of three different motion modes of the underwater nature objects and analyzed the propulsion mechanisms of different bionic underwater systems and of the existing problems in the development of the bionic underwater propulsion mechanism. This analysis of the use the new materials, existing decisions in bionics and intelligent control technology can be used in the development and design of the bionic thrusters for underwater robots.

Vortex pump is a kind of non-clogging pump, which will cause a large amount of vortex during transportation. Four kinds of mathematical model of vortex pump are introduced with continuous improvement. Moreover, the internal flow state, calculation and design method are also presented. In addition, the influent of slurry and structure parameters is introduced. After analyzed above, the design method of vortex pump can be further investigated specific to different concentration, viscosity and particle sizes under different specific speed. The focus of future research is testing internal flow by the advanced technology, building up a new flow model and proposing complete and practical calculation method.

During the actual operation the centrifugal pump will suffer a great energy loss due to the friction resistance between the fluid and the over current components and create great noise due to the hydraulic pulsation caused by the complex distribution of flow field In order to reduce resistance and noise it is significant to apply the bionics technology Through the observation and study of the natural biological characteristics some available bionic structure has been designed to improve the properties of centrifugal pumps Combined with the traditional resistance and noise reduction technology the bionics technology such as super hydrophobic pump non smooth impeller ladder tongue and bionic volute show efficient and simple functions of resistance and noise reduction In current studies bionics technology had abilities of reducing the friction resistance between the fluid and over current components improving distribution of pressure and reducing radial force It can be seen that bionics technology will be widely used in resistance and noise reduction of fluid machinery

Bionics is a new frontier science and provides many inspiration and thoughts for human invention. Through discussing the classification of bionics, it can greatly improve the capacity of human’s adaptation for nature and productivity as well. It can also have great social and economic benefits. Besides, the reason that restricts bionics development is expounded. Development of bionics can’t last long without the cooperation with many other subjects, and its own development also promotes the development of these disciplines. Furthermore, it is development trend of bionic that to achieve more perfect imitation and reengineering of nature, to discover and develop its relevant theories and technical methods. Therefore, bionics plays more and more important role in innovation and has broad prospects in the research.

The earthworm is a common terrestrial animal, its physical structure and morphology characteristics are very distinctive. Through of imitation of the special abilities of earthworms, people can get the material to research on bionic technology, such as the jet, non-smooth surface, etc. It can provide the new design ideas for engineering technology. The study of earthworm body structure and its movement mechanism, can help people to find the drag reduction method in the process of movement. In addition, the earthworm non-smooth body surface, dorsal pore jet, surface lubrication, electroosmosis and its unique moving way form a good drag reduction effect. Therefore, research on earthworm is instructive for the development of bionic technology.

With the development of world’s economy, energy shortage gradually appears. Resistance has a great influence on energy consumption. In other words, drag reduction means saving energy. Development of the drag reduction technology plays a very important role to improve the energy efficiency. Therefore, drag reduction technology of jet has become a hot research field. Drag reduction technology of jet is applied on the surface, so as to reduce surface friction resistance. Through analyzing the necessity of energy efficiency increase and jet drag reduction theory improvement, research progress of lateral jet flow technology and drag reduction technology of jet in the field of aircraft are reviewed. Besides, a main trend on the drag reduction technology of jet research is presented.

With the development of economy, the energy problem is becoming more and more seriously, which is closely related to resistance, and drag reduction means to save energy. Research on the technology of drag reduction plays an important role in the area of energy saving and its utilization rate enhancing. Using the method of bionic surface drag reduction to reduce the surface friction drag in a fluid medium has become a hot topic in the research area of drag reduction. Furthermore, through analyzing approaches of bionic surface drag reduction on the necessary of energy saving, energy utilization rate enhancing and drag reduction theory system improving, the research progress of the dynamic bionic non-smooth surfaces and bionic jet surface drag reduction technology are summarized in detail, the main trend of non-smooth drag reduction technology research and jet drag reduction technology is reviewed.

The inner flow analysis of centrifugal pumps has gradually become an important issue for the hydraulic design and performance improvement. Nowadays, CFD simulation toolbox of pump inner flow mainly contains commercial tools and open source tools. There are some defects for commercial CFD software for the numerical simulation of 3-D turbulent internal flow in pump, especially in capturing the flow characteristics under the off-design operating conditions. Additionally, it is difficult for researchers to do further investigation because of the undeclared source. Therefore, an open source software like Open Field Operation and Manipulation (OpenFOAM) is increasingly popular with researchers from all over the world. In this paper, a new computational study was implemented based on the original solver and was used to directly simulate the steady-state inner flow in a double blades pump, with the specific speed is 111. In order to disclose the characteristics deeply, three research schemes were conducted. The ratios (Q/Q d ) of the flow rate are 0.8, 1.0 and 1.2, respectively. The simulation results were verified with the Particle Imaging Velocimetry (PIV) experimental results, and the numerical calculation results agree well with the experimental data. Meanwhile, the phenomena of flow separation under the off-design operating conditions are well captured by OpenFOAM. The results indicate that OpenFOAM possesses obvious strong predominance in computing the internal flow field of pump. The analysis results can also be used as the basis for the further research and the improvement of centrifugal pump.