Numerical investigation on autonomous underwater vehicle hydrodynamics

Abstract

This research project deals with hydrodynamic modeling and parameter optimization of Autonomous Underwater Vehicle (AUV) geometry. The main approach for prediction and optimization is based on CFD techniques. The proposed research plan represents the continuity of other investigations supported by FAPESP on prediction of hydrodynamic derivatives of AUVs (see project number 07/56646-5). In this project it is investigated numerical tools for predicting added mass, viscous drag, static lift and dynamic efforts acting upon an AUV. Results produced by the CFD approach is going to be compared to those ones derived from experiments and analytical and semi-empirical approaches.Considering the static efforts of lift force and moment produced by a fixed angle of attack, the investigation is supposed to complement former studies that have been carried out using a typical shape, the Myring geometry, adopted in AUVs such as Remus. In this project, more streamlined shapes are going to be investigated. Those ones have been tested in towing tanks already, and the experimental results will be used for validating the numerical prediction to be produced in this research. After validation, a comparative analysis between Myring and streamlined shapes will be carried out from the point of view of maneuverability. The estimation of dynamic efforts (lift force and moments produced during the vehicle rotational movement), CFD results are going to be compared with those ones included in the literature, the experimental results produced by PMM tests, and the predictions derived from analytical and semi-empirical methods.The panel method is going to be investigated for predicting added mass efforts.Finally, based on the construction of proper grids and increased computational resources, this project also includes the investigation of the viscous drag prediction based on CFD techniques. (AU)