Kugel Fountain: Ball
Pressurized water flows between the sphere and socket, creating a mechanical fluid bearing that is nearly frictionless.
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You could get it to roll a bit, but that took some effort. The water was barely flowing out through the small seam between the ball and the big opening below it. As for pressure difference, the water pressure up on the bottom of the sphere has to be equal to the weight of the sphere plus the air pressure down on the sphere. Well, more accurately the air pressure down on the top of the sphere, symmetrically oriented to the water area below.I was wondering how much the water pressure is and what kind of calculation we need to find out the water pressure. I wanted to create a small fountain that would make the ball float. You can lift a very heavy ball with a well calculated thin film of water, with an outwards flow and a variation of cross section in the two dimensional channel formed between the partial hemisphere of the ball and the support. It’s the same effect than hydro-planning. The pressure acting at any point on the ball by the water is not related to the ball at all. This is the same affect as hydroplaning as mentioned before.
The World’s Largest Kugel Ball is a 29+ ton granite ball floating on a thin film of water on display in front of the Science Museum of …
The same principal is applied to the main crankshaft bearings in a car where oil is injected at a higher pressure and the crankshaft rotates on a cushion of oil. The weight of the ball can be much larger than the water displaced if you have dynamic pressure under the ball. Water is being forced in under pressure, creating a cushion of water. Besides which you would need make a lot of assumptions such as the bowl and ball surface being parallel, which they aren’t likely to be. I think there’s a trick to making this work well. The weight of the ball then can be calculated, subtract the weight of water it displaces, and the remaining pressure needed to hold the ball above the cylinder is the pressure you need. To determine the ‘height’ above the cylinder rim the ball would float then, is simply a function of flow rate. The gap between the cylinder and ball times the circumference gives you a flow area. Then you need a single pressure drop calculation to determine flow velocity and you’ll get the volumetric flow rate. The ball in cylinder model would work a lot better than the ball in bowl model since it eliminates the need to do a pressure distribution calculation. You can make the bowl look like a bowl, but simply pinch down around the circumference. It’s a classic problem – the pressure only has to equal the pressure of the ball over the area of the inlet ( or something – it’s been a while). They aren’t that difficult to make, if you rub a roughly spherical ball in a roughly spherical base they will both polish to the same radius.
It’sthe same principle as making spherical mirrors – except easier since you don’t care about the final exact radius.
How easy it is to push the ball off it’s mount depends on how far up the sides of the ball the mount comes.
What do you notice about the granite ball and its cradle? Would you be able to spin this granite ball if it was sitting in a dry dish? It sits within a cradle that has water being piped from its base. Mains pressure water is pushed up under the ball and spreads out across the base of the granite ball. The push of the water is just enough to lift the ball about one tenth of a millimetre against the pull of gravity. The water also acts as a lubricant when the ball spins.
In engineering workshops, liquid or air is often forced underneath heavy objects, to act as a lubricant and allow objects to move easily across or past each other. We will send original shipping documents to you upon receipt of balance for you to pick up the goods timely. Please let us know the quantity and detailed requirements so that we can advise a production schedule.
Please feel free to feedback immediately if you are not pleased with our provided quality or service. We can supply you the best quality and good price of the item you would like to order. We warmly welcome the stakeholders home from and abroad come and visit our factory and establish a long-term good business relationship. About 16% of these are stone garden products, 2% are granite, and 1% are pillars.
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Honing And Polishing A Granite Ball
Using power tools and abrasives to hone and polish granite. Captured with Canon Powershot A470. Edited in Picasa.