Abstract
In this paper, we will present an approach to compute the signed distance or level set function from the Standard Triangle Language (STL) file format. Then the level set is used to represent the surface of a given object inside the computational domain. The continuity and Navier-Stokes equations are solved numerically to study the fluid flows over the solid body. The finite-volume method (FVM) is applied to approximate all terms in the governing equations to conserve mass and momentum. The cut-cell method is employed to avoid recomputing the mesh points when the body moves around. The transport equation for the level set function is solved accordingly to update the position of the object.