variavel0=<b>Ana Lúcia Fernandes Lima e Silva</b> - alfernandes@mecanica.ufu.br Universidade Federal de Uberlândia
<b>Aristeu Silveira-Neto</b> - aristeus@mecanica.ufu.br Universidade Federal de Uberlândia
<b>João Jorge Ribeiro Damasceno</b> - jjrdamasceno@ufu.br UFU
<b>Abstract.</b> In this work, a immersed boundary method is applied to the numerical simulation of an uniform flow over several geometries. The force source term, added to the two-dimensional Navier-Stokes equations, guarantee the imposition of the nonslipping boundary condition over the body-fluid interface. These equations are discretized using finite differences method. The immersed boundary is represented with a finite number of Lagrangean points, distributed over the solid-fluid interface. A Cartesian grid is used to solve the fluid flow. The key idea is to propose a method to calculate the interfacial force without ad-hoc constants that, usually, should be adjusted with the flow and with the numerical method, whenever this kind of model is used. In the present work, this force is calculated using the Navier-Stokes equation applied at the Lagrangean points and then distributed over the Eulerian grid. The main advantage is the possibility to calculate this force field, even if the interface is moving or deforming. It is unnecessary to localize the Eulerian grid points near this immersed boundary. The lift and drag coefficients and the Strouhal number, calculated for an immersed cylinder, are compared with previous experimental and numerical results, with good agreement, for different Reynolds number. Qualitative results are also obtained for flows over a square cylinder and over an airfoil.
<b>Keywords.</b> Immersed-Boundary Method, Eulerian-Lagrangean Formulation, Drag Coefficient, Finite-Difference Method.