Why still no dive acceleration difference?

[TomcatViP]

What I said most importantly :

Transonic drag being far higher than low subsonic drag, low rpm is better either for your eng (max pow dive) and for your total drag coef.


But I hve to agree that was not my best writing

I think that your answer lies in faisability (large series) and techniques.

Just remember that the very goal of the Clark's Y airfoils series is for an easy craftsmanship (russians abused of this with their wooden series of La, Yack etc... all were made out of Clark Y).

Propeller material:
German = wood (but some 109 had metal..... seems it was not so much a prob ?)
US = casted aluminium

It makes a huge difference in what kind of airfoil you can achieve.

But still it's only my own guess.

Thx for making that thread an interesting one. Pls go further on

EDIT :OOOpss..just forgot to say that the Clark Y airfoils had a flat bottom to ease marksmanship.

[BlackBerry]

Tomcatvip, if you exam the fw190a8 max level flight at 20000ft, you will find the tip of VDM propeller is just 1 Mach.

680km/h TAS, 2700rpm engine, 0.54:1 reduction ratio, 3.3m diameter

[TomcatViP]

IMHO it's a by-design parameter. Don't we hev the same result with the larger Hamilton props such as fitted on the P47?

[Crumpp]

IMHO it's a by-design parameter. Don't we hev the same result with the larger Hamilton props such as fitted on the P47?

Yes, the engineers in the 1940's were at the top of their game for subsonic propeller design.