In order to execute a dunamic simulation consistent with its purpose, it it important to carefully select suitable mathematical models in view of their prediction capability and complexity of their mathematical expression. The authors have been developing a proto-type system of mathematical model selection support expert system for a dynamic simulation of nuclear thermal-hydraulics. The function of the proto-type system is to support the selection of both fluid model and constitutive equations in liquid-vapor two-phase flow analyses.
In this study, the proto-type system is improved in several points: (1) the system development environment is changed from an expert system shell to an object-oriented multimedia development enviroment Macintosh HyperCard to increase the user-friendliness of the proto-type system, (2)the calculation cost estimated to be necessary for a dynamic simulation is considered in the model selection, and (3)the Analytic Hierarchy Process(AHP) is applied to determine the weights of criteria for the selection of constitutive equations. The effectiveness of the improved system was examined by several examples of weights extraction by AHP and model selection of both fluid model and constitutive equations. As the results,(i) the AHP is shown to be effective to extract the weights of selection criteria from the image of analyst, and (ii) the system gives reasonable selection results consistent with the simulation purpose of analyst.