You could bolt the hub (or weld, if it is steel) onto a base. Use one tapered roller bearing in the top. Drop your turntable shaft through it and down through a pillow block bearing.
Here's a steel hub with bearings for less than $20.
https://www.surpluscenter.com/item.a...catname=wheels
EDIT: Didn't notice how small it (the turbine) is. A flanged bearing in a piece of wood should do fine. I used to get 5/8" ID sealed flanged bearings from Northern Tool, in the go-kart section. If you don't need precision, hand truck wheel bearings might work - you can get a whole wheel for about $4. on sale at Harbor Freight. Magliner sells their "precision" red bearings for about $2. each.
http://www.magliner.com/index.php?pa...mart&Itemid=30
If you are a decent woodworker and have some hard maple, make some wooden bearings.