Fundamental concepts of modeling

This paper addresses the roles of simulation in science and engineering: the extended calculator, the prototyper and the intuition generation medium. Science and engineering involves thought processes which transcend the rational. Simulation has emerged as a third wing of science that is orthogonal to experimentation and theory. It has the pedestrian role of the extended calculator in the simulation provides a numerical bridge between symbolic theory and hard experimental data. In this role, discovery has been assisted. But, simulation has proved to be more than a super calculator. The nuclear industry and computational fluid dynamics are but two examples of areas that use simulation to replace experimentation (prototyping) for cost and danger reasons. Further, there is an emerging role of graphics and artificial intelligence in the discovery process. Simulation is clearly becoming not only a tool that reduces the tedium, but one that enhances the creative process. The paper looks at thermalhydraulics and considers the emerging trends. A general modelling scheme is proposed and a systems view is used to suggest the criteria for optimum simulation models for the working environment. The basic theme proposed is to reduce the proportion of rational mental time we spend on perspiration so as to allow more time for inspiration non- rational. Our QUEST then is the Quintessential Eureka Stimulator. The QUEST involves the use of existing tools on the microcomputer to enhance problem setup and post-run analysis. The key to successful questing lies, however, in the development of a simulation environment that is seamless through the whole of the process, from problem definition to presentation of results. The framework for this mythical environment is introduced