Research On Hydrodynamic Thrust Vector Nozzle Technology Of Underwater Robot

With the increase of mission complexity,it is difficult for the existin.g underwater robots to meet the requirements of multi-tasks,so a new way of propulsion and manipulation is needed to improve the mobility of underwater robots.In this paper,a new type of underwater robot propulsion and control technology,namely the hydrodynamic thrust vector nozzle technology,is proposed based on the fluid thrust vector technology in the field of aviation.The structure design of the vector nozzle was completed,the assembly and debugging was carried out,the experimental platform was set up,and the multistage pump flow test was completed.Four parameters,including the control force,the main flow variation coefficient,the secondary flow efficiency and the fluid thrust vector Angle,were proposed to evaluate the mechanical properties of the nozzle.The structure parameters of the vectoring nozzle were fixed,and the jet orifice width was 2.4mm.The influence of six different secondary flow rates on the thrust vector characteristics of the fluid under four different mainstream working conditions was investigated,and the corresponding relationship between the main flow and the secondary flow was obtained.Then,the influence of the outlet surface and the width of the jet nozzle on the thrust vector characteristics of the fluid is studied.The results show that different main outlet surfaces have a great influence on the control force,which determines the maximum potential of the vector nozzle in deflection performance.Too large jet nozzle width will lead to the instability of the entire system,resulting in a large thrust loss.However,there is no relevant theory for nozzle selection,so it is necessary to optimize the mainstream outlet surface under a given working condition.Vectored nozzle numerical calculation method for the research,this paper introduces the geometric thrust vector nozzle shrinkage than prototype in this paper,fluid processing and grid generation,in order to improve the calculation precision of numerical model,after comparing different turbulence models and different boundary layer upon layer number on flow field of the manipulation of the force as well as the mainstream,eventually determine the relevant numerical parameter Settings,used in the physical prototype of vector nozzle simulation optimization.High precision numerical calculation model is determined,in view of the physical prototype model based on agent on the surface of the export of mainstream optimization the first export of mainstream surface the 3 b spline curve is used for the parameterized modeling,Latin hypercube experimental design was generated after the 120 groups of representative parameters calculation,in order to establish the agent model of high precision,explores the polynomial response surface,the error of the neural network and the kriging model,finally the elliptical basis neural network is adopted to establish the agent model of nozzle,based on the isight after on the island more genetic algorithm is adopted to optimum nozzle agent model,determined the best surface configuration.