DETERMINATION OF SELECTED PARAMETERS IN A 1D OPEN CHANNEL FLOW MODEL

Abstract

Determination of the model’s parameters is an important stage of mathematical models’ application. In the case of a free-surface 1D unsteady flow model defined by the de Saint-Venant equations, one of the groups of parameters to be estimated is the set of parameters describing energy losses due to friction. The parameters can be estimated in different ways, but in most cases the task of their determination is an ill-posed problem. In such cases, optimization methods are the most common approach. In spite of numerous examples of such applications, these techniques are still not fully recognized, as there are several problems of different nature that require thorough analysis. Automatic optimization methods are discussed in the paper. The most important questions of choosing the objective function and the optimization algorithm are considered. Problems connected with data reliability and accessibility and their influence on the solution are discussed. The most common pitfalls of optimization applications are discussed. The analysis is supported with numerical examples.

Keywords

• determination of parameters
• optimization procedures
• well-posed and ill-posed problems
• numerical methods