Physics-based Numerical Simulation of AUV Self-propulsion UsingMulti-block Hybrid Dynamic Mesh Method

A multi-block hybrid dynamic mesh method for physics-based numerical simulation of AUV (autonomous underwater vehicle) self-propulsion motion is presented. The method models a fully appended AUV with rudders and propeller, uses UDF (user defined function) to transmit force and velocity between AUV and its propeller, adopts 6DOF (degree of freedom) motion equations to solve the motion parameters, and employs the dynamic layer method to update meshes. Finally, the numerical simulation of AUV self-propulsion motion is achieved which models the straight ahead run from the static state to the uniform velocity. The differences of the self-propulsion velocity, the wake fraction and the thrust deduction factor compared with MFR (multiple frames of reference) are 2.6%, 3.7%, and 6.8%, respectively. And the computation convergence is speeded up compared with the unstructured dynamic mesh method and the dynamic overset mesh method. By numerical simulation, the velocity curve, curves of thrust and resistance, contours of wake velocity and pressure, and related animations during AUV self-propulsion are obtained. The physical reasons of interaction among the hull, the propeller and the rudders are investigated, which provides a physics-based numerical simulation method for more complex maneuvering motions of marine vehicles.