A practical exercise in simulation model validation

The validation of continuous system simulation models is a matter of great practical importance. Unfortunately, however, it often receives very little attention in university-level courses on modelling and simulation. The paper considers some possible reasons for the lack of emphasis given to model validation issues in education and describes an exercise which has been designed to introduce students to some practical aspects of internal verification and external validation of nonlinear dynamic models. The work involves a laboratory-scale system based on two inter-connected tanks of liquid and also demonstrates some important limitations of a widely-used nonlinear model. Features which make the chosen system particularly suitable for this teaching application include the relatively simple physical nature of the system and the fact that all the key variables of the model are accessible for measurement. Students are exposed to a range of practical issues, such as the selection of the sampling rate for data c...