## Centripetal Backflow

Like ring B which runs all the way around, we now have ring F (shaded in light blue). Water enters tangentially into this ring, flows radially inwards towards the system axis and then leaves this ring via conduit H (shaded in dark blue) towards the turbine cone. As within ring B, here too, the water flow in ring F is rotational, and here again, the relatively sharp redirection occurs without significant frictional losses, practically like a ball-bearing.

As the water moves, at all times it's centrifugal force is directed on to the wall at right angles to the wall. Because of the direction of this centrifugal force, the water flows off ring F in a tangentially inward direction. The volume of the ring reduces the further inwards it goes but it opens further as it approaches conduit H allowing additional space for movement. Thus, water is directed inwards to the smaller radius at the system axis and this motion is not opposed to the direction of the centrifugal forces which are radial to the system axis.

Water from ring F now runs in an axial direction towards the turbine inlet. However, the inlet water needs to be rotating around the system axis when it reaches the inlet to enable the necessary centrifugal forces to be produced. Consequently, the water needs to enter the space between the turbine cone and the inside wall at an angle of about 30 degrees through the turbine inlet. That redirection of flow, (inwards and towards right side of the diagram) to become a rotational flow (around the system axis and towards the right) is achieved by conduit H. Fins are installed in this section, directing the water from ring F radially inwards. These fins are gently curved in the direction of system rotation, so water is guided by slight angular deflections towards the turbine inlet E, ending up with the required 30 degree angle.