The fluid turbo machinery essentially consists of an impeller rotating in a casing. Fluid enters the eye of the impeller (the center of the impellers) and exits though the space between the impeller blades to the space between the impeller and casing walls. The velocity of fluid elements is in both tangential and radial directions, as the impeller rotates. The velocity as well as the pressure, both increase, as the fluid flows through the impeller |