-1
$\begingroup$

I am trying to create an HRE (Hybrid Rocket Engine) and i am trying to find the best oxidizer. Do any of you have experience with using helium?

$\endgroup$
  • 1
    $\begingroup$ You should read wikipedia about helium and noble gases as well as about helium compounds. $\endgroup$ – Uwe Mar 9 '17 at 21:05
  • 2
    $\begingroup$ I'm voting to close this question as off-topic because it lacks very basic research efforts. $\endgroup$ – SE - stop firing the good guys Mar 9 '17 at 21:11
  • $\begingroup$ i am going to delete it myself in 10 min... $\endgroup$ – Coen van Woudenberg Mar 9 '17 at 21:24
  • $\begingroup$ @CoenvanWoudenberg are you really asking about helium as an oxidizer, or are you saying that 1) you are looking for the best oxidizer, and 2) you are also interested in adding helium to the mixture for some reason? $\endgroup$ – uhoh Mar 11 '17 at 2:37
4
$\begingroup$

Helium is a noble gas, meaning it does not react with other atoms. In fact, it is the least reactive of them all. No compounds containing helium has ever been found, although some of the heavier noble gasses have formed unstable compounds. As helium can not be part of any molecule, it can not release chemical energy in any way thus failing to be an oxidizer. It is in fact the worst possible oxidizer. Take a look at liquid oxygen or fluorine instead.

$\endgroup$
  • $\begingroup$ You should read wikipedia about helium compounds too. $\endgroup$ – Uwe Mar 9 '17 at 21:07
  • 1
    $\begingroup$ @Uwe Those are not really compounds in the way we usually interpret them. They are exotic ions forced together under extreme conditions. Here is the link for those wishing to read it: en.wikipedia.org/wiki/Helium_compounds $\endgroup$ – SE - stop firing the good guys Mar 9 '17 at 21:09
  • $\begingroup$ But under a very high pressure, helium does react with other atoms to build compunds. But no helium compounds stable at normal pressure have been found yet. $\endgroup$ – Uwe Mar 9 '17 at 21:14
  • 1
    $\begingroup$ @Uwe: Of course energy of such bond is totally dwarfed by energy of the state the compound is in. And that state makes any use of the compound completely impractical, e.g. a tank to contain 1.7GPa of stable Cristobalite HE II would completely dwarf the mass of substance contained, and the energy of decompression from 1.7GPa to the ~100kPa of atmosphere would totally overshadow the meager energy of the compound breaking up. $\endgroup$ – SF. Mar 13 '17 at 12:02
  • 1
    $\begingroup$ OTOH, helium would make a very nice propellant. If we manage to build ion engines capable of ionizing helium, they will have a total overkill of specific impulse. $\endgroup$ – SF. Mar 13 '17 at 12:03

Not the answer you're looking for? Browse other questions tagged or ask your own question.