props: tractor v pusher, q tip, ducted?

Charles Talleyrand wrote in
oups.com:

On Aug 7, 7:34 am, Bertie the Bunyip wrote:


The drag is induced by the cooling itself.

How can the drag be induced by the cooling itself?


If I understand
you, the same cowling with the same air flow shows significantly
different drag depending on whether the engine inside is hot or cold.

I honestly don't understand that.

Not what I mean. the flow inside is quite different with the prop
turning or not, though.

I'm away at the moment, but I'll look in my library when I get home for
a better definition than I can provide off the top of my head..K?

In any case, It's Cessna's claim nd not mine that cooling drag was
sorted on the airplane.

I also recently read an aricle in a very old Sport aviation about the
pros and cons of pusher/tractor arrangements. I can't remember if the
author came up with a definitive answer as to which was better or more
efficient, but I don#'t see how he could, really.



Bertie