| Re: OT Interesting video
Matt O'Toole wrote:
> On Thu, 18 Jan 2007 16:40:11 -0500, Ken C. M. wrote:
>
> > Michael Press wrote:
>
> >> Can you can tell me why gas turbine engines are not practical? They
> >> have run well in races.
>
> > Ask Chrysler they tried to get one to work in a prototype back in 70s
> > and it went nowhere fast.
>
> Turbines are actually less efficient and pollute more than modern diesels,
> so they're a non-starter for car/truck use.
I think you are thinking about a specific application - aircraft
engines. A well-built turbine should come out near twice the
efficiency of a diesel with the same output. But it would cost several
times as much to make.
If diesels were more efficient, we would not use turbines in power
plants, where even tiny efficiency advantages make significant profit
differences.
> On top of that, they're expensive, run at too-high RPM, and have a narrow
> RPM operating range. They're more suited for constant speed, high load
> applications, like generators and aircraft/marine propellers.
A constant speed, high-RPM case could be made for turbine-electric
hybrids, but if it really would work, I would expect diesel-electric
locomotives to be replaced with turbine-electric.
Austin
> Turbines are well suited for aircraft because of their light weight,
> compact size, reliability, and relative efficiency. Light weight and
> compact size makes for a smaller plane which requires less power, etc.
>
> An Indy race car is a relatively constant speed, high load application,
> where light weight and compact size are important too. Thus Granatelli's
> effort in the 60s, which would have won if not for a broken fuel pump.
>
> Matt O.
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