Based on the techniques presented in previous chapters, many practically relevant problems can be handled effectively. In this chapter, selected examples are presented to illustrate the effectiveness of the computational and modeling techniques detailed earlier in this book, such as the multiblock method, multilevel modeling, turbulence closure, and volume averaging for phase change problems. The cases presented are diverse in nature, including the turbulent fluid flow inside hydraulic power plants, the double-diffusive flow in a thermohaline stratification, and the vertical Bridgman growth of NiAl crystals. Both the physical relevance of these problems and the computational issues associated with these cases are discussed. An attempt is made to describe the physics associated with these problems in some detail, but the intent is more to provide a flavor of the dynamic and geometric complexity of some representative practical problems of engineering interest that can be handled by the techniques presented in this book.

Flow in a Hydraulic Turbine

The first case involves turbulent flows in a hydraulic turbine. The geometries used in the computations to be presented are that of components of a hydraulic turbine including the distributor and the draft tube.

Distributor Flow Computations

In the following, a discussion of the distributor flow computations will be presented to shed more light on the application of the multiblock technique. Two distributor configurations are considered.

CASE A: 5 BLADES

In this configuration, a single periodic sector consists of two fixed stay vanes (first row of airfoils) and three pivoting wicket gates (second row of airfoils).