Imagine you are driving a car on the road. You are going straight, and at a certain point you encounter a sharp left turn. The car then tends to move to the right due to centrifugal force.
Centrifugal force and flow
The formula is: Fcₚ equals V squared divided by R. If you have a pipe through which water flows, where all the droplets together form the flow of water, you can compare this to driving straight ahead in an orderly manner.
What happens in a 90-degree bend
The moment a 90-degree bend appears in the pipe, the water, just like a car on the highway, suddenly has to go around the corner. At that moment, you can see that the water droplets are pushed toward the outside of the bend. The flow no longer moves through the bend in an orderly way.
The flow changes from balanced to unbalanced. This can lead to the formation of air pockets (unbalanced flow).
Implications for pump suction
When dealing with a pump, it is important to ensure that the supply to the pump has a balanced flow. That is why there are restrictions stating that no bend may be present within a distance of ten times the diameter of the suction pipe leading to the pump. After all, once the water has passed through the bend and flows straight again, the flow stabilizes.
