Pitching Control Simulations of an Underwater Glider Using CFD Analysis

An underwater glider is a type of autonomous underwater vehicle (AUV) that utilizes a small change in its buoyancy to convert the vertical motion to horizontal ones with help of wings. In order to examine the performance of an underwater glider, the state variables associated with diving such as forward speed and pitching angle are to be simulated at the initial design stage. In order to do it, the driving force of the glider must be estimated, which is a function of the advance speed and the angle of attack. In this paper, a simulation program for pitching control is developed to help the design of underwater gliders rationally. Instead of approximate formulations for hydrodynamic forces, the motion simulation code uses hydrodynamic coefficients obtained from a CFD(Computational Fluid Dynamics) code. Using the simulation program, the performance of a glider is examined in terms of the velocity or the diving angle and the capacity of the buoyancy engine and mass-moving are determined.