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01-19-2007, 01:50 PM

Isn't the RX-8 a rotary engine? And I owned a RX-2..2 plugs per rotor,
btw, not one.
jobst.brandt@stanfordalumni.org wrote:
> Michael Press writes:
>
> >>> But how about this concept:
>
> http://www.starrotor.com/Engine.htm
>
> >> After gazing at hundreds of "miracle engine" articles over the
> >> years, I've decided to ignore any reports that don't include tests
> >> of working models. The only one of those hundreds of designs that
> >> gained any traction was the Wankel, and it didn't set the world on
> >> fire.
>
> >> That page is way too full of phrases like "...is projected to
> >> have...", "...should be...," "...is expected to be..."
>
> > Can you can tell me why gas turbine engines are not practical? They
> > have run well in races.
>
> Interestingly, the Wankel first found real fertile soil at NSU in
> Neckarsulm (from which the name arises) just north of Stuttgart where
> I was working at the time. n R&D engineer came rolling in into our
> shop at Porsche to demonstrate this new concept.
>
> At the time I mentioned to the engineers to mark my words, that this
> engine will not survive, to their utter amazement... and that of all
> the others who wanted to believe in it. My thermodynamics Professor
> had shown us running rotary prototypes in the lab from years past and
> explained why they cannot work. They all have the same feet of clay
> as they address only the mechanical part of the machine and fail to
> see that this is a heat engine and thermodynamics its main focus.
>
> Essentially one spark plug for multiple rotating combustion chambers
> is what kills it. At the spark plug, temperatures in the 1000's degF
> occur if the engine has any reasonable efficiency, while the intake
> zone is below freezing (carburetor icing). Both areas remain a steady
> state.
>
> It's the reciprocation that makes it work. We use aluminum pistons in
> a mundane engine block with steel valves that see temperatures from
> freezing to flaming in one cycle. The average temperature when seen
> through a boundary layer of gas is mundane. Meanwhile the Wankel
> burns up! To make it work, compression had to be low giving poor
> performance, requiring higher engine speed to make up for that poor
> performance. The result is a short lived machine with poor fuel
> economy.
>
> When I read about propelling bicycles with the arms in a sprint or why
> mechanical stress relieving doesn't work, I recall these engineering
> moments where conventional thinking stymies understanding. You can be
> sure that I found no takers at Porsche. Professor Kays at LSJU had it
> right, although I believe his class failed to see the importance of
> his lecture and that was years before Felix Wankel presented his
> engine. That's often the way school is.
>
> The Wankel is dead!
>
> Jobst Brandt

01-19-2007, 01:50 PM	#50 (permalink)
qui si parla Campagnolo Guest Posts: n/a	Re: OT Interesting video Isn't the RX-8 a rotary engine? And I owned a RX-2..2 plugs per rotor, btw, not one. jobst.brandt@stanfordalumni.org wrote: > Michael Press writes: > > >>> But how about this concept: > > http://www.starrotor.com/Engine.htm > > >> After gazing at hundreds of "miracle engine" articles over the > >> years, I've decided to ignore any reports that don't include tests > >> of working models. The only one of those hundreds of designs that > >> gained any traction was the Wankel, and it didn't set the world on > >> fire. > > >> That page is way too full of phrases like "...is projected to > >> have...", "...should be...," "...is expected to be..." > > > Can you can tell me why gas turbine engines are not practical? They > > have run well in races. > > Interestingly, the Wankel first found real fertile soil at NSU in > Neckarsulm (from which the name arises) just north of Stuttgart where > I was working at the time. n R&D engineer came rolling in into our > shop at Porsche to demonstrate this new concept. > > At the time I mentioned to the engineers to mark my words, that this > engine will not survive, to their utter amazement... and that of all > the others who wanted to believe in it. My thermodynamics Professor > had shown us running rotary prototypes in the lab from years past and > explained why they cannot work. They all have the same feet of clay > as they address only the mechanical part of the machine and fail to > see that this is a heat engine and thermodynamics its main focus. > > Essentially one spark plug for multiple rotating combustion chambers > is what kills it. At the spark plug, temperatures in the 1000's degF > occur if the engine has any reasonable efficiency, while the intake > zone is below freezing (carburetor icing). Both areas remain a steady > state. > > It's the reciprocation that makes it work. We use aluminum pistons in > a mundane engine block with steel valves that see temperatures from > freezing to flaming in one cycle. The average temperature when seen > through a boundary layer of gas is mundane. Meanwhile the Wankel > burns up! To make it work, compression had to be low giving poor > performance, requiring higher engine speed to make up for that poor > performance. The result is a short lived machine with poor fuel > economy. > > When I read about propelling bicycles with the arms in a sprint or why > mechanical stress relieving doesn't work, I recall these engineering > moments where conventional thinking stymies understanding. You can be > sure that I found no takers at Porsche. Professor Kays at LSJU had it > right, although I believe his class failed to see the importance of > his lecture and that was years before Felix Wankel presented his > engine. That's often the way school is. > > The Wankel is dead! > > Jobst Brandt