Exhaust Heat Recovery - Steam Power

[FastPlastic]

I know it's been a little while since the last post. Just wondering if anyone considered the Tesla Turbines. From what I understand they are a series of disks that you jet steam at the edge. Sounds relatively simple to make.

Tesla Turbine Concepts Explained

[Dr. Jerryrigger]

yup, that's been brought up. It still seems like the best second choice to me, the first being a old pneumatic tool's turbine (due to ease of construction).

[FastPlastic]

Originally Posted by Dr. Jerryrigger

yup, that's been brought up. It still seems like the best second choice to me, the first being a old pneumatic tool's turbine (due to ease of construction).

Cool. Kinda skimmed over the thread again, so I guess I missed that post.

[Daox]

The idea hasn't lost steam (har har). I still want to make one. I do actually think that the tesla turbine would be easier to make, but neither are going to be easy. I have found bearings capable of handling the higher rpms that the turbine may see. I just need to find a way to make a shaft and spacers that can handle high rpm.

[ConnClark]

In Tesla's day Tesla turbines held were marginally better than competing turbine designs in the application for commercial electrical production. Using them for other applications one must keep in mind Tesla turbines have a few fundamental flaws. They don't respond well to input variations as well as variations in load. As a load is applied to them their efficiency plummets rather quickly as the load increases. They also don't handle high temperatures well as the discs start to warp.

That said for a homemade low temperature steam turbine they may be the easiest solution. On a car they just won't be very efficient.

[Daox]

Do conventional turbines handle variations in load better? I would tend to think not.

[Phantom]

Go to a local computer repair shop and ask for some dead hard drives to make the tesla turbine. See Build a 15,000 rpm Tesla Turbine using hard drive platters

[Daox]

You still need to make a custom shaft to hold the disks.

[Christ]

The motor itself will hold them, you just need to attach the motor to something. Unfortunately, I don't think HDD motors will actually generate anything, so that poses another issue.

As someone mentioned before, the Tesla Turbine's efficiency drops severely as it gets loaded down. Since it relies on the surface tension of flowing fluid to power it, instead of mechanical force (yes, I know, surface tension is a mechanical force), it doesn't respond well to changes in either input or output.

This is why I never mentioned it, even though they're one of my favorite study subjects.

[ConnClark]

Originally Posted by Daox

Do conventional turbines handle variations in load better? I would tend to think not.

Yes they do. Conventional turbines operate on the defection of mass. A Tesla turbine relies on cohesion of the air sticking to the rotors. A sudden change in supply flow or load breaks this cohesion and generates turbulence that drops its efficiency.