This chapter looks at how fluid moves through a circular set of blades without energy losses. When fluid flows through these circular blades, its direction changes from moving in or out toward the center. In real-life machines, the fluid first flows in a straight line before being redirected sideways. The flow might also have a side-to-side speed. While in a straight set of blades, only the blades cause changes in the fluid's speed and pressure; in a circular setup, these changes happen in front of and behind the blades too. The velocities also change with the distance from the center in a circular arrangement. Imagine each small blade to be part of a straight line even in a circular layout.