[AR] Re: coaxial injectors, venturi effect

  • From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
  • To: Arocket List <arocket@xxxxxxxxxxxxx>
  • Date: Fri, 29 Jan 2021 10:19:32 -0500 (EST)

On Fri, 29 Jan 2021, Peter Fairbrother wrote:

...I was wondering whether this might allow you to only use one high pressure pump for the LOX, and use the Venturi effect (if that is the correct name) to pump the fuel.

The term you're looking for is not "venturi" but "jet pump".

I'd go along with Norman on this one: it's not ridiculous, maybe you could make it work, but it seems likely to be more trouble than it's worth.

One issue he didn't mention is that if you're doing regen cooling with fuel, now the inner wall of the cooling jacket is also the pressure vessel, which will tend to make it thick and require strong materials -- not good for thermal conductivity. And low-pressure fuel will boil more easily.

(If you were trying this, probably pumping the fuel and using it to pump the oxidizer would be better. Aside from the cooling issues, the oxidizer pump is traditionally the hard part of a pump system -- more materials issues, harder to lubricate and seal, and harder to debug because the failure modes tend to be violent enough to destroy the evidence.)

Henry

Other related posts: