P-47 Zoom climb

Well the problem is a small advantage in this area is hard to make use of. Even if you come out 200m above and 50 Km/h faster than your opponent at the top of a zoom, he can still be shooting the whole way up. Not to mention any sort of rolling or jinking on the way up and the margin decreases even more. Really you need significant separation to start with as well.

If you are rolling and jinking while they are straight in smooth, then yes, the margin of advantage would be less.

What if you are rolling and jinking and they are following your rolls and jinks? Wouldn’t the margin of advantage stay (relatively) the same?

What if you are rolling and jinking and they are rolling and jinking even harder as they are trying to lead their guns on you? Wouldn’t your margin of advantage increase as they were flying more aggressively?

Really depends on range. The further away, the less the low guy has to really follow anything you're doing and more just needs to adjust aim slightly. Not to mention the problem of deflection shooting goes away with a very slow or stationary target.

And if the low fighter is close enough that they have to follow your maneuvers exactly then you probably don't have an energy advantage either :smilewink:

Lets say even then that you manage to make it to the top of your Zoom without eating Hispano for breakfast, and are now a few hundred metres above a spitfire what are your options to turn it offensive? You can try to do some sort of hammerhead (very difficult in DCS) or flatten your zoom into a low speed spiral climb/turn near the top, and try to get an angle to turn in on him for a gun shot. Not so easy to do, especially against a spit IX, which has excellent P/W ratio and low speed maneuverability, undoubtedly better than whichever energy fighter you just tried to zoom away from him in. So now you are slightly above an airplane that turns much better and will accellerate/climb better at the top/endof the zoom than you, trying to fly your high wingloaded Energy fighter at minimum speed in the hopes of a chance at a very small window for a high deflection snapshot. In my experience this usually doesnt work in DCS, and ends in you trying to dive away again. For whatever reason it works much better in the other WW2 sim, probably has to do with easier gunnery, and low speed control effectiveness in that sim/game.

So even to try it you should probably be at extremely high speed to begin with, which probably means you should have some altitude to start a dive before you zoom as well.

Not sure if a high speed climb isnt the better option in the end. There are more options to turn it offensive, to get help from a teammate, or to simply disengage (without being vulnerable at the top of a zoom as you would be otherwise) as well. This video shows an example of how to do something like this..... Once again easier in that game than in DCS though.

Back when the spit was released you could kill them with a zoom climb, but that was mostly because most people fried the Merlin while hanging on the prop at full power :lol: Has been patched out since then though :)

Waste gate automatics maintains not MP but the pressure at turbo nozzles (backpressure), so it is an absolute pressure aneroid (vacuum).

 

If you mean Merlin supercharger, yes, it's vacuum aneroid switch with hysteresis. No ram.

One more if I may. After researching on this, I am getting mostly modern references to "Variable Geometry Turbo's", "Variable Vane Turbo's" or closer to your usages "Variable Nozzle Turbo's".

So in effect, an Aneroid device measured exhaust gas back pressure at the entrance into the exhaust turbo nozzle, and adjusted Waste Gates automatically on this reading - or more accurately, Waste Gates reacted to this measurement via some mechanical linkage?

In effect, creating a primitive Variable Vane turbocharger??

Again, many thanks, I find understanding all the interactions of the P-47 and engine management fascinating!

I am not sure but all these references seem to me as something like variable vanes of the blower itself (except the last one) as it was in Jumo-213 or AM-35 engines. These means change blower pressure ratio at constant rpm. The last one means variable geometry (area) of the nozzles.

P-47 turbo was absolutely straight forward device and the rpm, so its power, was set by setting P_nozzle/P_outside ratio.

If you have no waste gate gas flow and backpressure are physically linked depending on nozzle area. As it is fixed you can only dump a part of gas flow bypassing the turbine through the waste gate.

Thanks Yo-Yo - I realize I am combining modern terminology and a pure wastegate operation Turbo from that era. Trying to visualize that physical connection or electro/mechanical operation of how the wastegates were operated and the effect on the Power Plant, along with the use of the Boost lever.

I did find a couple references to a electro/mechanical interface for exhaust back pressure, but no real diagram. Also found a picture showing a braided steel cable, housing some type of tubing exiting the turbo-supercharger.

I imagine this would be the pressure sensing device, and at some point a coupling whether electrical or mechanical was used to control wastegate operation at varying altitudes - along with pilot operation of the Boost lever.

Appreciate your time describing what you know, very helpful. ED's modeling of this airframe is remarkable considering the complexity of the mechanical supercharger coupled with the turbocharger.

Apologies for my rudimentary understanding, and poor use of terminology!