The Electric Car
in [Design]
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From: Rich Grise on 8 Oct 2007 20:04 On Mon, 08 Oct 2007 12:24:07 -0700, John Larkin wrote: > We're mainly engineers here, not overly concerned about money. Got a few spare thou you could send this way? Thanks, Rich
From: Michael A. Terrell on 8 Oct 2007 20:21 BradGuth wrote: > > On Oct 8, 12:24 pm, "Michael A. Terrell" <mike.terr...(a)earthlink.net> > wrote: > > BradGuth wrote: > > > > > Why do you and/or why would Warren Buffett hate the truth and > > > otherwise have such disdain against our badly failing environment? > > > > Why do you continue to post your lies and hatred? > > Now that's our warm and fuzzy semitic Michael A. Terrell, isn't it. Another thing you have no clue about, but it doesn't stop you from posting your usual ignorant drivel. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida
From: Michael A. Terrell on 8 Oct 2007 20:24 John Larkin wrote: > > [1] Funny how I always dislike guys named Larry. We have a friend who > used to be Larry, nice guy, but last year he changed his name to > Jerome. So, you don't like Larry the cable guy? I think that is Dimbulb's day job. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida
From: John Larkin on 8 Oct 2007 21:50 On Mon, 08 Oct 2007 14:23:38 -0700, Fred Abse <excretatauris(a)cerebrumconfus.it> wrote: >On Mon, 08 Oct 2007 12:01:40 -0700, John Larkin wrote: > >> Feed pumps are always a big problem on rockets. They have to be light, >> enormously powerful, pump nasty stuff, and are designed to run under >> major stress for a couple of minutes. > >Feynman's point was that they were expected to run under major stress for >a couple of minutes, then do it over again on the next launch, and so on. >He considered the lifetime predictions to be flawed. Yeah, he was pretty smart. And the Shuttle was pretty dumb. John
From: Glen Walpert on 8 Oct 2007 22:11
On Mon, 08 Oct 2007 14:23:38 -0700, Fred Abse <excretatauris(a)cerebrumconfus.it> wrote: >On Mon, 08 Oct 2007 12:01:40 -0700, John Larkin wrote: > >> Feed pumps are always a big problem on rockets. They have to be light, >> enormously powerful, pump nasty stuff, and are designed to run under >> major stress for a couple of minutes. > >Feynman's point was that they were expected to run under major stress for >a couple of minutes, then do it over again on the next launch, and so on. >He considered the lifetime predictions to be flawed. He might have been right about the projections, although lifetime projections are normally correlated against test data before being accepted as meaningful. I never heard of any problems with the oxidizer turbopumps failing in flight, have there been failures? My first engineering job was seal designer at Stein Seal Co. where I did part of the design of the shaft seals for a large Rocketdyne oxidizer turbopump around 1979 or so. One seal kept liquid oxygen out of the bearings, and the other kept a hot hydrogen and steam gas mixture out of the same bearings, with several inches between the two. Overall construction is similar to other turbopumps like automotive turbochargers, with a turbine on one end of the shaft and a pump on the other, seals and bearings in between. Neither fluid is what I would call "nasty" in this case; neither corrosive nor erosive. (We also did seals for really nasty fluids.) There is quite a bit of thermal expansion and contraction to be accomodated on startup, but not that much different from the bearings and seals used on jet engines which also have to accomodate a lot of slop for thermal expansion. A somewhat complicated design, but are they really "big problems"? |