Our objective is to demonstrate the efficacy of object-oriented programming for the development of scientific and engineering analysis software. We illustrate this through discussion of our application of object-oriented programming to computational fluid dynamics. We have written an object-oriented code in C++ employing the finite element method for the solution of transport-phenomena problems. Our emphasis is chemical engineering applications. The code solves the continuum equations of fluid dynamics, heat transfer and mass transfer with chemical reactions. In principle, the number of chemical reactions is limited only by the computing facilities that are available. New reactions are easily added to the system via the input data to the code. To demonstrate the code, we present original research simulating electroplating into a small pit with a fluid jet traversing the top, as occurs in circuit-board manufacture. We used a fully coupled transient model of the fluid dynamics and electrochemistry, and tracked the growth of the electroplated surface. We describe how this work was facilitated by the use of object-oriented programming.