Determination of hydrodynamic derivatives of an ocean vehicle using cfd analyses of synthetic standard dynamic tests

Abstract

A synthetic method of dynamic test for identifying hydrodynamic coefficients (HCs) of an ocean vehicle has been proposed. The methodology consists of simulating various planar motion mechanism (PMM) tests simultaneously in a single numerical analysis. As a technical method, a stationary numerical domain has been used. Therefore, non-inertial forms of the fluid flow governing equations have been solved for simulating sinusoidal tests in a stationary numerical domain. Consequently, the quality of the grids has been preserved during the analyses. With considering of the well-known underwater geometry of DARPA-SUBOFF, validation of the numerical simulation results has been done with the computing of the pure sway and the pure yaw tests. The PMM maneuvers were induced to the numerical analyses by using a user-defined function augmented to the solver. The current results are in good agreement with the experimental ones reported in the literature. Based on the superposition rule which can be used for combining dynamic tests, a synthetic test has been designed consisted of the pure sway and the pure yaw tests. It has been developed to form more advanced synthetic tests consisted of the various PMM tests as well. The test has the capability to use for deriving non-linear HCs as well as the liner ones. The efficiency of the proposed method has been compared with the other methods, which shows it is comparable to the other approaches.