In the present paper, we have proposed and applied a new Object-oriented modeling and programming paradigm to the CFD problems, especially to the Navier-Stokes flow problems. The modeling procedures are integrated and reconstructed according to the Object-Based (OB) modeling and programming paradigm, which is one of the Object-oriented paradigms. Throughout this integrated OB modeling and programming process,an Object-oriented (or OB), flexible Navier-Stokes numerical simulation system has newly been developed and applied to the actual flow simulation problems. We have also developed the integrated support environments, for example, the body shape definition GUI tool, the computing nodes handling tool, the visualization system, and the Object-Based Repository (OBR), etc.. From the simulation results of this system we have verified that (1) the OB modeling and programming methodology, (2) its actually developed fluid flow simulation system with the aid of the integrated support environments, are very valuable, flexible and useful for the domain users in the CFD field. This system powerfully helps the CFD simulation user to search and discover the essentials of the simulated fluid flow world in detail without any tedious troubles and with the satisfactory simulation controls. (C) 1998 Elsevier Science Ltd. All rights reserved.