[AR] Re: electric turbopumps
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: arocket list <arocket@xxxxxxxxxxxxx>
- Date: Mon, 10 Apr 2023 12:14:56 -0400 (EDT)
On Mon, 10 Apr 2023, James Fackert wrote:
Well, there's this orbital rocket maker that is working to replace
hydraulic gymbal actuators with electric, is already using high power
density electric motors from an associated electric car maker for
control service actuators, and that company has deep motor generator
high powercontrol expertise, builds their own electronics, has carbon
fiber wrapped rotor thousandish horsepower motor generators in mass
production.The rocket maker has pretty impressive full flow cycle rocket
engines in mass production now. What would you say the odds are that
there might be high speed electric motor/generators in the turbine power
loops now or in the future?
Completely unknown; insufficient data. Just because you've got a shiny
new hammer, *doesn't* mean that every problem looks like a nail, not when
examined carefully.
Replacing a drive shaft (not even a gearbox) with a generator/motor pair
is a big jump in complexity and cost. There needs to be a really good
reason. A staged-combustion engine needs a *lot* of pump power -- that's
why you resort to staged combustion in the first place.
The replacement is especially unappealing if the drive-shaft solution is
already working.
Don't need a motor and a generator. One device spins it up, manages a
difficult high power loop, and provides lots of auxiliary power for
electric actuators and such.
If you need serious power for actuators, it could easily make sense to add
a generator to a turbopump shaft -- it's common to hang auxiliaries on
them. That's a *separate* question from whether you try to replace the
drive shaft with a generator/motor pair, which is much more challenging.
Henry
Other related posts: