On Sep 24, 10:27*pm, tony sayer wrote:
In article , John Williamson
scribeth thus





tony sayer wrote:
In article , The Natural Philosopher
scribeth thus
tony sayer wrote:
In article , The Natural Philosopher
scribeth thus
tony sayer wrote:
In article , The Natural Philosopher
scribeth thus
tony sayer wrote:
In article , The Natural Philosopher
scribeth thus
Dave Plowman (News) wrote:
In article ,
* *Doctor *Drivel wrote:
More conspiracy theory. Dribble wants to replace a highly
inefficient
piston engine
This proves this person senile. Piston engines are approx 20%
efficient.
80% of the energy in the tank is wasted.
Wrong yet again. Try harder. Look up the efficiency of various types
running at their 'sweet spot' as you want. You might just learn
something
for once. But I doubt it.

no, dribble isnt far wrong in practice. Car engines dont run at
anything
like the sweet spot' most of the time.

JOOI where is this other energy wasted in heat or emissions or a combo
of both?..

Suppose I have say a 100 kW engine then 25 % of that is useful driving
the wheels energy, so where would or does the other 75 kW go to then
surely not all as heat?..

all as heat
if you mean a 30bhp car which is about what 25KW is.
Nope guv thats a 100 kW output engine and by the 25% *thats only 25 kW
useful which isn't strictly true for all throttle settings and imposed
loads.

That 100kw engine is using 400kw of fuel burn then.
OK .. the engine in my car is described IIRC that is as 98 kW

so its that its useful output, capable output, or what it consumes in
fuel of the equivalent of? ....
useful output.

Fuel burn 3-4 times more.

So then its dissipating under full throttle 300/400 kW?, Surely not?..

If you add it all up, yes. A *lot* of heat comes out of that exhaust
pipe in the hot gases. About 10 times the engine capacity every
revolution, at upwards of 300C.

I remember driving a coach in the early '80s flat out, and seeing (After
dark, of course) the red hot column of gases coming out of the exhaust
in the rear view mirror.

Just seems that it's the equivalent of 300 to 400 hundred 1 bar electric
fires?...

Thats a hell of a lot of heat!...

So it is. But the car engine runs on full power for just a few seconds
at once.
And not at all if the driver has any sense.