Build an Amazing Tesla CD Turbine

Step 6 Prepare the CD Spindle.

Drill holes in the CD Spindle as shown. Clean out the holes of shavings. De-burr and polish spindle post with 400 sandpaper or cleaning pad. If desired, install a half-inch barbed garden-hose fitting on the bottom outlet of the Spindle post. This allows a garden hose to be connected to the outlet. This works especially well if the CD Spindle Cover is hot-glued or duct-taped to the bottom lip of the Spindle tray for leak-free operation.

Comments

[Sazumo]

Er, I'm also doing a science project, and im wondering on how exactly the CD turbine works. My guess is, the big black inlet thingy is connected to the cd case and spindle and uses a water hose to shoot water through it. The water spins the cd's inside the case and then the water exits through the holes in the spindle? Also, could you help me come up with a topic concerning this? So far im considering "What is a tesla turbine and whats it do/how's it work?" Thanks in advance x]

[mrfixitrick]

You are correct as far as the basic way the Tesla Turbine works. The black thingy (sometimes green plastic or brass) is called the inlet nozzle. The nozzle is very important because it accelerates the fluid to a greater speed and kinetic energy before it spirals between the discs, where it imparts it's energy by adhesion through the boundary layer effect. There is good background info at wikipedia under "Tesla Turbine". "What is a Tesla Turbine and how does it work?" is a good start for a topic. The Tesla disc design works on a principle taking advantage of the adhesion characteristics of a fluid. I think an interesting topic would be to show what makes a Tesla Turbine different from other types of turbines. For example, the disc design makes the Tesla turbine able to take shocks and changes in fluid better than other types. A Tesla turbine was recently tested as being the only turbine type that can take 100% biomass combustion gasses without failure. What is it that you find fascinating about the Tesla turbine? When you look deeply into that question, and "follow your passion" as they say, you will find the topic that is best for you. Are you planning on building a CD turbine as demo model?

[Sazumo]

Thanks, and yes I am planning to build a CD turbine as a demo model. I was thinking of comparing the tesla turbine to a wind turbine? If so, should i build a simple wind turbine too?

[kusrox]

I was wondering if you knew the pressure of the water coming out of the turbine. I'm doing a science fair and its really important that the pressure coming out isn't too far from whats coming in.

[mrfixitrick]

There are two basic types of turbines...Impulse and Reaction. Tesla Turbines are primarily a reaction type turbine and as such will show a loss of pressure at the outlet.

The pressure loss through the turbine is variable depending on disc size and spacing, nozzle design, exhaust outlet size and design, rpm, and a few other factors.

It's hard to measure the water outlet pressure; in most cases it simply exits at atmospheric pressure or a few psi above.
A smaller centre outlet builds pressure, increases torque at a lower rpm. Larger outlet equals more rpm and power. less pressure.

It's possible to run several turbines in series, with the exhaust of one feeding the nozzle of the next. In that case, the pressure drop through each turbine might in the range of 5 or 10 psi.

For more info and formulas, see this page at Phoenix Turbine....

Hope this helps with your Science Fair project. Ask me more if this is not clear enough.