VW Reality

wrote in message
...
'Economy of Scale' in that smaller
engines are LESS thermally efficient than larger engines

Back before I got thrown out of engineering school, I was taught that if you
double all of the dimensions of something, the volume increases by a factor
of eight, but the surface area only increases by a factor of four.

The question posed was "Is there an upper limit to the size of a bird?" The
answer given, as I remember it was yes. Because the lift of the bird's wings
is proportional to area, but the weight of the bird is proportional to
volume, at some 'size', the wings become overloaded.

The same reasoning was applied to body cooling. The birds cooling was
proportional to surface area, but the heat produced was proportional to
volume.

What did I miss in EE102 after I transferred?

Birds aren't engines. See...

http://people.bath.ac.uk/ccsshb/12cyl/

....note the references to the thermal efficiency and specific fuel
consumption of smaller engines.

-R.S.Hoover

wrote in message
...
Birds aren't engines. See...

The same concepts apply. Unfortunately, I was applying the wrong concepts. I
mis-understood the term 'thermal efficiency'.


http://people.bath.ac.uk/ccsshb/12cyl/

That's one nasty engine!


...note the references to the thermal efficiency and specific fuel
consumption of smaller engines.

AH HA.


-R.S.Hoover

Thank for the extra help for the slow.

- Steve (Another one not left behind)