Chapter 4 - CFD models

Abstract

In this chapter, computational fluid dynamics (CFD), as an advanced technique in hydroinformatics modeling, is presented. Some representative applications of CFD in hydroinformatics including the one-dimensional solution of advection-diffusion equation in pollutant transport modeling, one-dimensional solution of Saint-Venant equations for dam-break simulation, quasi-two-dimensional solution of velocity distribution in compound rivers, three-dimensional modeling of turbulent flow, and finally pollutant transport in rivers are introduced and numerically solved. In this chapter, different types of CFD models are developed and used in different fields of river engineering simulations. The physically influenced scheme (PIS) is introduced for the one-dimensional dam-break modeling via finite volume method. PIS is used for the one-dimensional solution of advection-diffusion equation in pollutant transport modeling and one-dimensional solution of fully dynamic Saint-Venant equations in dam-break simulation. For solving the quasi-two-dimensional flow in natural rivers, the Shiono and Knight Model (SKM) with finite difference method is numerically solved. In the case of three-dimensional modeling, seven turbulence models are used to simulate the three-dimensional turbulent flow in open channels. Finally, three-dimensional pollutant transfer in rivers is simulated by three different numerical models. At each section, the outputs of numerical models are compared to the analytical or measured values to evaluate the results of the techniques. This chapter briefly introduces and applies CFD techniques in hydroinformatic modeling.