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Posted: Mon May 28, 2012 9:43 am
by DYI
but if you have a check valve BEFORE the meter, no dead volume would have to be calculated, right? :roll:

like a check valve between the fuel and the metering chamber, and a check valve between the air/oxidizer supply.


Nope. The oxidizer flow will still flush the fuel into the chamber and leave oxidizer in the meter, resulting in a slightly rich mix :wink:

Posted: Mon May 28, 2012 10:29 am
by Labtecpower
ahhh, now I understand :D

so i'll have to keep the meter volume as low as possible.

Posted: Mon May 28, 2012 11:15 am
by ramses
DYI wrote:
but if you have a check valve BEFORE the meter, no dead volume would have to be calculated, right? :roll:

like a check valve between the fuel and the metering chamber, and a check valve between the air/oxidizer supply.


Nope. The oxidizer flow will still flush the fuel into the chamber and leave oxidizer in the meter, resulting in a slightly rich mix :wink:

Okay, I was messed up because I use a quick disconnect and have two removable meters. You would get a lean mixture if you fuel through the propane meter.

Posted: Fri Jun 01, 2012 12:07 pm
by 8tonsemi
Is the formula that JSR gave me manometric or volumetric because Fnord said it was volumetric if that was the formula for volumetric can someone give me the formula for manometric.I don't think hybrid fueling 101 talks about it. If it does I'm sorry for not seeing it. So help with this would be great. Thank you. :lol:

Posted: Thu Jun 07, 2012 12:46 pm
by DYI
8tonsemi, if you can't do something as simple as deriving the necessary fuel pressure for yourself, you really shouldn't be building hybrids. The only thing you need is an equation of state (EoS) for the gases in question, and in all "spudding" application to date, the ideal gas EoS is perfectly fine. As such, you need approximately grade nine level math to figure this out for yourself.

Posted: Thu Jun 07, 2012 1:21 pm
by 8tonsemi
I don't actually build hybrid's yet I'm just gathering information so when I decide to try to make one I'll be prepared.