Research On Small External-rotation Vertical Jet Drag Reduction Testing Platform

Recently, there is a growing trend of research projects on reducing frictional resistance between the surfaces of liquidity and solidity, due to the energy crisis globally. Similar projects require large amounts of test equipment for liquidity drag,in which water channels and water tunnels are widely used. Among various techniques used in the area, bionic jet drag reduction attracts wide interests among scholars both inside and outside of China, which also requires sufficient experiment equipment. Potential problems with the experiment equipment,such as huge space occupations, high costs, operational difficulties, and inability to achieve surface jet function, have brought inconvenience to bionic jet drag reduction research.Therefore designing and developing a less spacious but well-functioned experiment equipment is extremely meaningful for the development of this technique research. Under the grant of Natural Science Foundation of China (NSFC) project, "Research on characteristics and mechanism of bionic jet drag reduction"(51275102),this article aims to develop experiment equipment that can successfully support such bionic jet drag reduction research.Based on the coaxial rotation circulation theory, this article compared and analyzed external-rotation vertical design as core platform structure. It also brought up the total design scheme of small jet drag reduction testing platform to satisfy the design requirement.Within the computational domain of experiment-simplified model, this article conducted qualitative analysis on the movement of coaxial rotation circulation to get the distribution of velocity and pressure of the liquidity mass points between two circulations; simulated the circulation movement under the state of turbulence flow using numerical simulation techniques to achieve distribution graphs of velocity and pressure of the liquidity mass points under different rotational speed; and proved the stability of flow environment using Rayleigh criterion.Under the flat boundary layer theory, the flat boundary layer was reconstructed by the coaxial rotation circulation movement at the state of non-jet to get the force per area of each discrete point in different main flow field velocity. It further integrated the force values of flat boards after the reconstruction of boundary layer,and compared the results with actual values to establish the ratio principles.This article provided a whole supply plan with self-circulation function and completes design procedures for other parts of the testing platform, based on the basic structure of small jet drag reduction testing platform. It analyzed the principles for other important procedures and proved the feasibility in practice as well.This article also introduced the accomplishment of the purchase, production, assembly,and test procedure of the machine elements for small jet drag reduction testing platform, and the conduction of bionic jet drag reduction experiments.