On Thu, Feb 11, 2021 at 07:24:41PM -0500, Henry Spencer wrote:
On Thu, 11 Feb 2021, Norman Yarvin wrote:
...Having the rotor acting as a pump seemed like an easy alternative to
turbopumps...
Well, it's an *alternative* to turbopumps, but the "easy" part is more
doubtful. :-) Trouble is, it means that your engines spend their working
lives at very high G, and this tends to make hot metal sag... and making
it thicker *doesn't help* because that adds mass too! Jeff Greason said
(some years later) that in such a system "you have to clever your way out"
of every stress problem, and that it really made him lose enthusiasm for
rotating machinery. Hence the change of approach.