Since grid computing provides users with more distributed computing and storage resources, it gives us an opportunity to design new efficient and robust solvers for the numerical solutions of partial differential equations (PDEs). For instance, large scale problems in computational fluid dynamics (CFD) can be efficiently simulated under this environment. However, unfortunately, most of the currently developed PDF. solvers using the finite element method (FEM), usually tight combinations of a mesh generator and a linear system solver, are not qualified for the grid computing environment. In this paper, based on principles of grid computing, we present a grid-enabled Client/Server model for solving the Stokes/(incompressible) Navier-Stokes system in 3D.