sci.energy

On Sat, 16 Feb 2008 06:08:09 -0800, your dog wrote:

> Here is a description of the tesla turbine.
> /wiki/Tesla_turbine
>
> Here is a video I found.
> /watch?v=ordrp4KXEKQ
>
> I consistently hear about the Tesla Turbine as being "crackpot."
>
> I have the greatest respect for Tesla and his work, and it makes me sad to
> find his name associated with crackpottery. Some of his later work makes
> that understandable, but I feel it should be considered in the context of
> the state of science when he did it. Lord Kelvin was another great
> scientist, and he made some quite wrong predictions that people make fun
> of him for, and I think that's unfair too.
>
> I want to know why it's a crackpot idea. I don't want to hear from pro-
> Tesla people. I want to hear why it's impractical.
>
> Problems I've heard:
>
> differential expansion from droplets: I don't see how this would be a
> serious problem.
>
> thermal expansion warps the disks:
> Seems to be a solvable material choice/arrangement problem.
>
> pressure/speed differences suck or blow the disks into each other: Seems
> to be a solvable inlet/outlet design problem.
>
> efficiency will be low at moderate power levels as fluid/disk speeds
> diverge:
> This seems to be a function of fluid used, disk spacing, rpm, and
> diameter. My napkin says that the Tesla Turbine ends up being
> substantially more efficient and cheaper than "conventional" impulse and
> pressure turbines for a number of smaller (that is, other than the "major"
> turbine applications like steam/water power generation and gas turbine
> engines) applications that turbines are used for now.
>
> So what am I missing?

It depends on friction rather than reactive momentum transfer, causing
irreversibility and unavoidable loss of efficiency. It's good for some
specialized applications, but not where efficiency in important.