[AR] Re: Peltier specifications

  • From: "Mark C Spiegl" <mark.spiegl@xxxxxxxxx>
  • To: <arocket@xxxxxxxxxxxxx>
  • Date: Mon, 3 Aug 2015 20:33:41 -0500

Wow... Im out of the office for a day and my inbox is full! :-)

Anyway.. Anyone who has followed my hybrid projects knows Im a fan of high
density Nitrous. Im looking to cool 20-50 lbs of Nitrous to 25-ish degF.

Goals:

(1) Flashing liquid to vapor to chill Nitrous is fine in a motor burning 10-20
lbs of Nitrous. Much above 20lbs (esp in the desert), flashing liquid to gas
becomes impractical. I would like to start a little closer to my target
temperature of 22 degF. The Peltier, Stirling Cooler, or whatever would chill
the supply tank, not the rocket tank.

I know ice is a quick-and-dirty answer, but I would like something a little
more elegant and deterministic. Bags of ice aren't a great answer at FAR or
Blackrock.

(2) I have had trouble igniting high density Nitrous in warm weather. Cold
weather is no problem. I cannot prove what is happening, but I suspect
temperature gradients in the long thin Nitrous tank are causing the problem. If
the Nitrous is 22 degF at the top of the tank, it may be much much colder at
the injector. Supplying Nitrous close to the final temperature should help
mitigate this problem, if Im correct.

A related question: Any simple ways to equalize temperature between the top
and bottom of the rocket's oxidizer tank???

--MCS

(Im an EE kind of person so my solutions tend to feel like electronics... ie
Peltiers)




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