Research On Drag Reduction Of Moving Body In Flow Field Under Multiple Working Conditions Based On Piezoelectric Vibrator

In recent years,the vigorous development of international trade has given birth to the international freight industry.Among all kinds of international freight modes,international shipping is most widely used.However,despite the advantages of large shipping volume and low cost,shipping has the same obvious disadvantages as its slow speed.This is ultimately because the resistance of objects in water is much greater than in air.Therefore,it is of practical significance and economic value to reduce the resistance of objects in water flow.The main resistance of the object in water is friction resistance.Under the inverse piezoelectric effect of piezoelectric ceramics,the friction resistance near the wall surface can be reduced by changing the coherent structure of the turbulent boundary layer.Based on piezoelectricity theory,hydrodynamics,tribology and mechanical dynamics,a set of flat plate drag reduction device is designed with modular design idea to study the change of underwater friction resistance and explore the change of friction resistance under different working conditions in this paper.At the beginning of this paper,some fluid theories related to the subject are introduced,such as boundary layer,and the friction resistance of laminar flow and turbulent boundary layer.Next,this article makes explanation on piezoelectric ceramics and piezoelectric theory.On the basis of these theories,this paper initially completed the model design and the research content.In order to obtain the friction resistance value of the model under the condition of no vibration,the equivalent model of the ideal plate is established.Then,the piezoelectric vibrator model is extracted separately,and the modal analysis,frequency response analysis and transient analysis are carried out by using the finite element software.Finally,the displacement curve and vibration equation of the node at the maximum deformation position are determined.On this basis,the dynamic grid is set up on the whole plate by using the flow field analysis software and a program is written to load the vibration law of the wall on the local area where the piezoelectric vibrator is located,so as to explore the influence of the different arrangement of the piezoelectric vibrator position on the plate on its drag reduction effect.In this paper,according to the three different positions of piezoelectric vibrator on the plate,the friction resistance of piezoelectric vibrator under vibration is simulated.In order to explore the influence of different working conditions on the effect of drag reduction,the same simulation analysis is carried out for the models with different plate thickness and different flow velocity,and the friction resistance under the condition of no vibration is calculated to get the respective drag reduction rate,and the drag reduction law is summarized and the reason for the change of resistance is analyzed.Finally,on the basis of obtaining the resistance variation law of the single piezoelectric vibrator model,this paper further analyzes the double piezoelectric vibrator model by simulation,and compares the resistance variation law of the single piezoelectric vibrator and the double piezoelectric vibrator in order to further determine the correctness of the results.