Although not a new technology for rockets, the propellant pump is one thing experimental rocketeers could well do with.
Unfortunately on the scale of size that most amateur liquid fuelled rocket builders are going for, the pump becomes a very complicated matter, it is often just as easy to use an onboard pressurization system, or run the rocket in blowdown mode (tanks filled to ~60% then pressurized with an external source before flight).
But with new technologies and 3D printing metal, small scale pumps may be in the realms of amateurs, this technology has notably been pursued by Ventions and Rocket Lab in the form of electric driven pumps. More so, Ventions who have been in the game a bit longer than Rocket Lab specialize in developing electric and turbine driven pumps as well as rocket engines on a small scale, news is generally few and far between, but one can find patents on the hardware never the less to get an idea of some of the things they are up to.
Rocket Lab Rutherford Lox/Rp-1 Rocket Engine
Other notable pump technologies is the piston pump from Xcor Aerospace, the pump will power their Lynx space plane on its suborbital flights.
More info can be found here.
Current Amateur Pump Work
There has been a little bit of pump work going on in the amateur community, I’ll try to detail some below, there may well be projects I have missed and or do not know about so do drop me a line to tell me!
Back in 2008 Paul Breed of Unreasonable Rocket looked into a geared Hydrogen Peroxide electric pump when doing an analysis for his NGLLC Level 2 vehicle, Paul went as far as building a pump system but as far as I can tell did not test it.
You can find the specific blog posts here, “Why I like this project…” and “Merry Xmas“
Not really amateur so to speak but Nadir Bagaveyev of Bagaveyev Corporation has been doing work with small-scale 3D printed pumps. Information is few and far between, but Nadir does have some good youtube videos of his work so far.
This is only one of many, make sure to check out his youtube profile.
Another project that got to testing phase is from Andrew Burns. Andrew set out to make a small electric centrifugal pump, pumping 0.3kg/s at 800psi using a Barske impeller design, the pump fluid power output is 1.5kW and runs as 40% efficient. I am not sure the current state of Andrews work, but never the less he shows what can be made with limited machining capabilities.
And lastly, a group of enthusiasts, professionals, and amateurs on the Arocket mailing list over the past few months have been working towards building a hydrogen peroxide and gasoline electric centrifugal pump. The project is utilizing minds and expertise from all over the world so it will be interesting to see how it progresses. Clicking on the link provided and going through the 2015 archives will put you in the right place to find out more without myself doing a huge info dump here.
Design your own pump
It may be up to you to help us amateur experimental rocketeers prgress more in the pump world so here is the literature and help needed to get started.
Design of Liquid Propellant Rocket Engines, a very comprehensive section on pumps, if you feel like it in hard copy, you can get it here, worth every dollar.
Centrifugal Pumps – Design and Application, recommended by others in the rocket world.
Centrifugal Pump Design, again recommended by others in the rocket world.
And lastly Lloyd Droppers of Project Earendel has been posting on pump design,