Let's go back to Basic Science 101 to review this concept. You can either do the actual science fair experiment or visualize it.
Testing Centrifugal Force
Are you ready to transport back to the 5th grade for your science fair project?
- Fetch a plastic bucket and fill it about halfway full with water.
- Holding on to the handle, straighten your arm and extend it in front of you.
- Using big sweeping circles, spin the bucket around and around, faster and faster, over your head, behind your back, past your knees, back in front, repeatedly.
- What happens? If done correctly, the water should stay in the bucket.
Empty the water from the bucket and make a small hole in the bottom of the bucket, then refill with the same amount of water. Perform the same spinning experiment as before, this time spinning faster. Does water shoot out of the bucket with more force as you spin the bucket faster? Note: If you make a larger hole in the bucket's bottom, more water will shoot out as you spin it around.
A centrifugal pool pump operates in a similar fashion. A component called an impeller in the pump spins, shooting water out of it. As more water leaves, a vacuum effect is created that demands more water to equalize the force. Water -- including unclean water -- is pulled from the pool or spa and goes through the circulation plumbing. Differences in the design of impellers, diffusers and volutes determine the amount and flow rate of a pool or spa pump.
Source: The Ultimate Guide to Pool Maintenance, (Terry Tamminen, McGraw-Hill, 2004).