I have been flying this sim for over a decade, and I really only know how to fly two planes well - I-153 and F4F-3. (Yes, I realize that neither of these was available in the initial release.) Is it safe for me to assume that I don't have to worry about the performance of my preferred rides in the 0.8 to 1.0 Mach range? ;-) ;-) ;-)

Cloyd

If you ever go that fast in an I-153, you have a problem. And almost certainly, no wings... ;)

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 :oops:

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.

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

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.

About the propeller on the Fw190V18?
 

Reading this very interesting topic a question has come to my mind: for what reasons did the enginneers at Focke-Wulf tried a four blades propeller on the Fw190V18 high altitude prototype (were the blades longer? was the propeller similar to those on the P51 and P47?). Anyone knows or have a guess?

They were looking for a counter to the B-29 being able to bomb at 30,000 feet and above.

The Germans had no ability to intercept anything at that altitude. The FW-190V18 was one of the designs examined and tested. The result was the Ta-152 series had better performance at altitude and the program was scrapped.

Thanks for the answer Crumpp,

In fact I was very surprised to see a German aircraft with a 4 blades propeller (which is very uncommon, the only other i know is He177 Greif bomber) , so i thought (in my noob mind) this solution would somehow be related to very high altitude flight (after all P47 used 4 blades prop and was designed as a high altitude aircraft, and when the P51 became one too, it switched its three blades for four). To sum up i thought the 4 blades were somehow related to very high altitude rather than to power dive performance. But it was just a noob question :) : anyway i recognize that i don't know anything about aircraft enginneering! Just trying to try to understand "in broad strokes"...

As for what you said about 4 blades propeller and cowling/wingroot weapons firing through the prop disc, although very rare, there were some aircraft with this configuration:

P39-Airacobra late 4 blades prop and P-63 Kingcobra, 2x50. cal (cowling) firing though the prop disc ;

Nakajima Hayate Ia, 4 blades prop and 2xHo103 MGs (cowling) firing through, and on later Ib version 2xHo5 20mm canon (cowling).

I've found any with as much guns (4) as the Fw190 though, perhaps four blades would have killed the high firing rate of these guns?

Hardly, the electrical priming on the Fw could deal with synchronised fire rather easily. Much better than other systems.