Otimização geométrica da popa de um submarino considerando sua eficiência hidro-volume e interação com propulsor e duto.

Abstract

This study developed a tool that aims to present the stern geometry with the best hydro-volume efficiency for an already designed propeller, using duct or not, within the concept entitled as full stern by literature. The tool allows the user to insert requirements and geometric restrictions in the selection process. The DARPA SUBOFF model was chosen as the reference model and its Semnan coefficient as the parameter. A code was created in the MATLAB software to generate the stern lines, where the requirements and geometric restrictions are inserted as way of selecting these lines. From the selected lines, geometries are created which will be evaluated in the Ansys software to obtain the hydro-volume efficiency and check the boundary layer behavior. The study was divided into three phases: bare hull, hull self-propelled and hull self-propelled with duct. The geometries and simulations in the Ansys software are carried out in an automated process. At each simulation round, the best geometry found is inserted into a search process for a new stern line based on a metaheuristic that guides and modifies the operations to produce new geometries with better efficiency. In the 1st phase, a stern is generated without interference from the propeller or appendages in the flow. In the 2nd phase, the MOD5a propeller is used, whose results are also used for tool validation. In the 3rd phase, the MOD10 is used without the stator in order to check the influence of a ducted propeller on the hydro-volume efficiency and compare it with the results of the previous phases. The results obtained from the selected geometries, when compared to the reference model, showed that the tool proved to be effective in conjunction with the adopted search strategy and the use of ducted propeller increases the hydro-volume efficiency of a submarine.