Simulation of Unsteady Flows with Applications in Aeroelasticity

Abstract

The advances in information technology and experimental methods have allowed the numerical and experimental study of more complex phenomena in Computational Fluid Dynamics (CFD), particularly for unsteady problems. The better understanding of such phenomena has decisively contributed in the design of more efficient systems and devices. The need for numerical simulation in CFD is justified by the lack of analytical solutions of the Navier-Stokes equations for most practical cases. One of the most common aspects in problems treated through CFD simulations is the domain geometrical complexity. The computational domain representation becomes the one of the first issues to be solved. Therefore, the geometrical modeling represents an important step, because it has as one of its main goals the adequate computational representation of spatial decompositions. In the context of aeroelastic problems, the major difficulty in the design of mathematical models still remains on the determination of the aerodynamic behavior. Aerodynamic flows present complex behavior, generally related to the velocity and the fluid features in the region of interest. This study is aimed at applying CFD methodologies for the determination of the aerodynamic operator in order to perform aeroelastic stability analyses in regimes in which nonlinear aerodynamic phenomena are relevant. Therefore, geometrical modeling, numerical methods in CFD and appropriate coupling procedures, for coupling the CFD aerodynamic model with the structural-dynamic formulation, will be the main focus of the present study. In this fashion, the work will comprise the following main objectives: (1) Modification of an existing CFD simulation tool in order to incorporate the capability of treating flows in which the meshes can move or deform; (2) Implementation of techniques which would improve the computational performance of such tool, enabling the efficient treatment of unsteady problems; (3) Aeroelastic analyses of aeronautical and aerospace configurations using the tool so developed in order to obtain the aerodynamic operator.