Air Temp Nitinol

[gadgetmall]

Tom . I have had no time to test this YET but i will . The design will use ground temp water bath for the temperature differential using just brass pulleys .
If i can find something finned i would try it . .

Air temp nitinol need only 25 degree difference and it will Immediately phase change around brass ,aluminum or copper  wheels without water in the above ground section. it is metal and can absorb the temperature of the air just as good by itself but metal wheels,especially in 21 degree air like we had a few days here where everything was cold . ..
Cold season appears not a problem but summer days like we had this year(116f) will need some serious cool water underground to touch and a finned wheel is a good idea at least for the below ground area.

i did a small test in 35 degree out side air with an excavated heat tube(produces steam) and of coarse that works very will with just brass pulleys in air .

AI have a lot of work to do . 

[Tom Booth]

Hi, I wasn't thinking in terms of your particular application. I don't know as a wire with aluminum fins would be able to go around a wheel. I was thinking more along the lines of a hot air engine where there would only be hot and cold air contact. Something like the design I posted earlier where hot and cold air would be passed across a nitinol wire (or wires) or springs by means of a Stirling type displacer arrangement to move the air.

The problem being that from my general observations, nitinol does not seem to respond quickly to air temperature changes. From what I understand or have read, such fins can increase the rate of heat exchange several times over in various other more conventional applications like heat pumps, air conditioners etc.

[johntee]

Hi Tom,

You have a very fertile brain, a great quality.

Personally I'm not too sure on the actual characteristics of Nitinol wire yet, I have some on order. Therefore I would open up such concepts as yours to our more experienced members for evaluation and feedback.

Thanks for your posting,

John

[Tom Booth]

Thanks,

Unfortunately, at the moment, my brain is much more fertile than my bank account, so I haven't gotten around to getting my hands on any Nitinol as yet. I could certainly afford the Nitinol. relatively cheap stuff. Building the engine to put it in and test such a concept however is a different story.

[Jon J Hutton]

I am amazed that Nitinol has not received more attention. Even if you can only get a few watts from a temperature gradient of 50 degrees or less, this could be multiplied. This is bound to make a huge comeback since its discovery. Good work. This has more potential than solar if the prodution price could drop. Is the air changing Ni dopped with Co or just Ni ?
P.S. I lived in Oklahoma for many years and now am a director of a school here in Guatemala. Less than 20 minutes from my house is a huge lake at the foot of an active volcano in the mountains. I took a thermometer with me and the sands of the beach in many places have vents where the temp of the sand stays at a hot 150 deg. F year round. The water just a few feet away during the winter ( winter here is where the temp drops down to 70 but it can get colder at nights. ) is approx 75. Before reading this thread I was considering a sterling app, but now am considering a new approach of a ni engine. Any help anyone could give would be greatly appreciated.