[en] A General Electric 3 x 3 rod bundle critical heat flux (CHF) experiment was analyzed by using BODYFIT-2PE. (Boundary-fitted coordinates-2 phase partially elliptic). BODYFIT-2PE is a three-dimensional, steady-state/transient, single-phase rod-bundle thermal-hydraulic computer program based on the technique of boudnary-fitted coordinate system. In this coordinate system, all the physical boundaries are made to be coincident with the coordinate lines so that the boundary conditions, such as constant heat fluxes and zero velocities, can be accurately represented without interpolation. However, the transformed coordinate system is not unique for a given geometric configuration. The more orthogonal the coordinates are, the faster the rates of calculational convergence. The generation of the transformed coordinates is based on the solution of a set of second-order partial differential equations, subject to a set of geometric boundary conditions. A simple Laplacian is used in the present study