Sketched Parametric Modeling in CFD Optimization

Abstract

In the field of shape optimization for CFD computations, users of geometry-modeling software normally have a wide variety of tools to choose from in order to parametrically design a hull from scratch and build a Fully Parametric Model (FPM). However, in practice most hull models are initially designed with no parametrization, and are then exported and imported between different software, normally forcing a subsequent required optimization to be performed in a Partially Parametric Model (PPM). These PPMs can sometimes be too complex for an average designer to build, since he may not be familiar with the mathematical constraints needed for the application of the required transformations, or the particular tools for given software to be used for the parametrization. In this context, a solution that can be introduced is sketched parametric modeling, which is the combination of complex geometry-modeling operations into intuitive, simple and user-friendly tools. By experience or input from adjoint/shape sensitivity analyses, designers may know where they would like their hull to be modified in order to improve CFD performance, and with the help of sketching, may parameterize those changes quickly to be input for a CFD optimization. This thesis presents an application of sketched parametric modeling in the parametric geometry-modeling and CFD integration software CAESES, and further use of it in a hull shape resistance optimization case using CFD viscous flow software FINE/Marine.