Simulation Study Of3-Dimension Current Sensor Based On Flow Field Analysis

The21th century is the century of ocean. For the sake of sustainable development and utilization of Marine resources, we need to use the ocean observation equipment to observe ocean, and the key component of the ocean observation system is current sensor. Throughout the research on current sensors of domestic and overseas, we lack a better method to measure three-dimensional velocity which has wider differences in three-dimensional distribution, especially on the measurement of upwelling and research on a new3-d current sensor is of great significance.Firstly, this paper expounds the background and significance of research on current meters, analyzing the working principles, advantages and disadvantages of current meters existing in both domestic and overseas. Then, by summing up their shortcomings, the research purpose of the paper has been cleared.Secondly, this paper introduces the basic theory of hydromechanics and CFD, elaborating the derivation of CFD control equations. Then it gives the details about the flow boundary layer theory and the related factors affecting rounding drag force. Lastly it lays emphasis on the introduction on the three-dimensional sphere flow around.Then, based on three-dimensional vector decomposition of velocity and lined with the current sensor flow field analysis.The change rules of drag and lift of the single sphere and thin disc are obtained at different velocities by simulating the flow field around the sphere and the disc based on Fluent. The measurement structure of current sensor is determined:measuring horizontal velocity by sphere structure and vertical velocity by thin disc, the structure model of the sensor is presented..By simulating the flow field around the whole structure of the sensor, the change rules of drag and lift on the sphere and disc of the sensor at different velocities are discussed and compared with the single sphere and disc. Through exploring the influences of the sensor structure to the drag of the sphere and lift of the disc in flow around, the structure design scheme of the current sensor is determined.Finally, the analysis of sensor structure modal and the fluid-structure interaction are done. The natural frequency of the sensor with the flow field and without flow field is analyzed and the frequency of the flow field is obtained by spectrum analysis. Through comparison, the frequency of the flow field around is far away from the natural frequency of the sensor, avoiding the resonance.