Why still no dive acceleration difference?

[BlackBerry]

The efficiency is nearly constant in any portion of the envelope that design can sustain flight....

That is the beauty of a CSP.

Crumpp, this thread is about DIVE, in a high speed dive, you can easily reach very high TAS which, of course, you can not sustain. Finally, as you pull out of dive and begin to level, the aircraft will slow down to its max. level speed, isn't it? The late dive peroid is a temporary flight process in which you may have 25% efficiency advantage over your opponent bacause both propellers could not maintain constant efficiency(85%), namely your 4-blade prop get 80% and your enemy just have 55%, this is a huge tactic factor. Forthermore, from dive terminal speed to max. level speed, that is the slowdown peroid, you still have efficiency advantage. So how long is your advantage peroid? 40seconds? 1 minute? It depends on your altitude to dive from. You are bleeding his energy in this peroid even if your enemy is the best pilot in the world! You are stealing his energy for 40 seconds by the "hand of God". Now you can run away with ease, out of his shooting range. This is called "OUTDIVE".

The very nature of power producers is such that the faster they go, the less thrust they produce. The reverse is also a characteristics of power producers. The lower the velocity, the more thrust they produce. That efficiency drop occurs because the propeller blades are stalled just like in very high speed flight. The reason is different but believe me, both realms, high and low speed, produce stalled blade portions. In the low speed realm, we are looking at speeds at taxi and the first part of take off but our thrust force is extremely high at low velocity. Therefore, in the scheme of things, it is a useless detail to include the reduction in efficiency in a dive. The performance is not sustainable in the first place and our reduction in thrust with velocity is already well approximated by:

As I said above, if you are stealing 500HP from your enemy for 30 seconds, he loses "hundreds meters altitude" energy! Imagine that in a il2 combat you decrease throttle to 65% for 30 seconds, that's suicide.

In a high speed flight, a little thrust will give you a lot power, don't forget:

Power=thrust*speed

It is output power not thrust determines your energy state.