Numerical Simulation Of AUV Self-propulsion Based On Moving Mesh Method

AUV plays an increasingly important role in the realization of seabed detection,marine geomorphological observation,military exploration and so on.Numerical simulation of maneuvering of AUV underwater can meet the requirement of safety and cruising performance.At the same time,it will make a contribution on the low cost of AUV and high efficiency.Self-propulsion test is an important experimemt to measure the AUV hydrodyanmics.This paper presented a self-propulsion simulation of a full appended AUV based on moving mesh method.The contents have three parts:Firstly,MRF(MultipleReferenceFrame)method was used to obtain the steady self-propulsion point of a full appended AUV.The full appendage of AUV includes AUV hull,tailplanes and a discretized propeller.The domain is divided into a rotating propeller domain and far stationary domain.The mesh is built by hybrid grids.SST turbulent model and RANS function are solved.A 'loading varying method' is used to obtain the approaching velocity,which keep the roating velocity RPM=300,and changing the advance velocity.The approaching velocity at self-propulsion point is 0.972m/s,and the discrepancy is 2.8%with the designed velocity of lm/s.This simulation provided an initial step for self-propulsion simulation using moving mesh method.Secondly,a UDF(User Defined Function)which has three parts was programmed to solve the motion of AUV in self-propulsion:1)Giving a constant rotating speed to acquire the thrust and torque of propeller;2)Transferring the thrust and torque to AUV,and obtain the velocity of the AUV by solving the 6-DOF equation combined with the force of AUV flow field;3)AUV speed will be transferred to the propeller to make its speed consistent with the AUV body's ·Finally,the numerical simulation of AUV self-propulsion is carried out by using the dynamic mesh method combined with MRF.In this paper,the rotational simulation of the propeller basin is carried out by using MRF.The direct mesh motion of AUV is simulated by moving mesh method.The speed is calculated from UDF speed of step 2).The cruise speed of the moving mesh numerical simulation is 0.9m/s,and the curve of resistance and thrust change and the velocity curve of the simulation are given.The velocity field,propeller wake field and corresponding pressure field of AUV at different speeds were obtained.