It is possible that a hydraulic machine will not give the desired result for
which it has been designed. Such a machine is costly for manufacture and once it is
made, it is difficult to change its components. Therefore, it is required to predict the
performance of a prototype hydraulic machine before it is manufactured. This is done
by making its model. Experiments are first performed on models from their results
the performance of the prototype machine is predicted chapter on "Dimensional and
Model Analysis" given in Fluid Mechanics will be useful for the prototype. Here
prototype and its model are two similar machines having different specifications,
which are to be compared. The concept of "Unit and specific Quantities" is a
prerequisite for comparison of hydraulic machines. In addition, in this chapter a brief
discussion about cavitation in turbine, turbine section, marking types of turbine and
hydraulic turbine classification and section according to hydraulic power plants.
Keywords: Cavitation in turbines, Similarity laws, Turbines classification and
selection.
