Turbine Cooling ?'s

[Zippiot]

My buddy wants to build a turbine powered boat and I was wondering if pumping water onto the turbine could extend its life? In the water you got a hopefully near endless supply of the stuff...

Would misting it onto the turbine wheel help at all or is there a more efficient/complex method?

[racketmotorman]

Hi

Please don't spray water on a turbine wheel , it'll probably wreck it .

A properly designed turbine engine shouldn't run temperatures too hot for its turbine wheel to handle .

Adding water to a turbine engine can be more trouble than its worth because of the changes it makes to the configuration between wet and dry running .

Why are you contemplating this drastic measure ??

What engine are you intending to use?

What are its temperatures?

Cheers
John

[Zippiot]

Nothing in the works, just wondering. Hobby turbines dont last as long as big expensive one b/c of cooling so we though there must be some way to cool a hobby turbine with all the water available in a lake.
Guy I talked is almost done with his 6 stroke piston engine, he uses water as the cooling and fuel for the final 2 strokes. Was wondering if there was a way to apply this to a turbine; such as some way of mixing the hot expanding/burning gasses with water for some flash steam and a bit cooler turbine running temps.
my comma button is broken it took 15 mins to add them to this post.....lol

[Zippiot]

Oh I forgot, the reason it came up was I have always used the cut and bend your own axial turbine method from the shrecky book. Never bought an Iconel one.
My Stainless Steel ones only lasted a few hours at the most.

[racketmotorman]

Yeh , homemade turbine wheels can be a problem , unless made well , their efficiencies are so poor that the engine has to run high temps so as to provide sufficient power to turn the compressor .

Better off using turbocharger bits to make the engine, like I did with my FM-1 engine... http://www.racketmotorman.turbinebuilde ... hp?album=2 ,....... TOTs are down in the 500 - 600 deg C range even though producing ~60 lbs of thrust at 85% rpm potential , expected thrust ~100 lbs at full rpm of 66,000 .

Plenty of ways to make reliable turbine engines using turbochargers

Cheers
John

[Zippiot]

Is the wheel made of metal or is it cermaic? Worked on many turbos over the last few years and came accross a few silicone-nitride ones. SHould have stolen them

Do you have a better source for turbo wheels than ebay?

[racketmotorman]

A lot of truck and auto turbo turbines are made from GMR235 or Inconell 713 , both "super alloys" capable of withstanding high temps , up to ~900 deg C turbine inlet temps .

But an engine is the total of all its parts , unless all components are working efficiently the engine won't perform , no point having a high temp turbine wheel if the compressor is running out of its design limits , and/or the combustor isn't producing a nice burn without flames in the turbine .

Most of the larger turbine overhaul shops have "bits and pieces" that could be used in a homemade engine , but aren't up to the standard for going back into a turbo which will see thousands of hours of use . You need to hunt around a bit )

Cheers
John