Re XCOR (US# 7854395 B1) patent which was filed in Feb of 2008 - issued in
2010 and discussed at that time on this forum:
As noted by Ben there were at least some doing it in the same time frame as
early XCOR efforts (well prior to the patent filing) and of course there
was a good paper titled, "Reusable Rocket Propulsion for Space Tourism
Vehicles" authored by Doug Jones of XCOR at an AIAA/ASME/SAE/ASEE Joint
Propulsion Conference in July of 2004.
It publicly disclosed the saddle jacket method employed by XCOR that put it
into the public domain well before the patent filing. Under section VI -
Long Life Features, page 6, one paragraph begins, "XCOR and others such as
the Swiss Propulsion Laboratory (SPL) have built regenerative engines using
separate chamber, throat saddle, and outer jacket."
It includes a picture of the SPL engine saddle jacket layout and discusses
the thermal stress benefits etc over about 1 page. The paper is well worth
reading for this engine design and other reasons.
Cheers
Brian Feeney
On Wed, Dec 30, 2015 at 8:09 PM, Ben Brockert <wikkit@xxxxxxxxx> wrote:
CSJ then introduces the issue of buckling of the chamber wall. For good
regen the chamber wants to be thin, for good structure it wants to be
thick.
In addition to XCOR, CSJ has been done by Masten, SPL, Scott Zeeb, BURPG,
and others.
On Wednesday, December 30, 2015, Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Wed, 30 Dec 2015, Brian Feeney wrote:
Does the Saddle / Jacket engine design alleviate much of the inner to
outer differential thermal wall stress by way of the inner wall (chamber /
nozzle) sliding relative to the outer wall.
XCOR's patented (US# 7854395 B1) design lets the inner wall expand both
axially (by sliding within the jacket) and radially (by building the jacket
as a loose fit at room temperature, so it's only a snug fit -- not a
crushing constraint -- with the inner wall hot). In principle this could
avoid much of the problem. In practice the details probably matter a lot...
Henry