Quote:
Originally Posted by camber
Crumpp as others have stated, Steinhilper is clearly not complaining that rookies fell behind because of their inability to manually duplicate a CSP (i.e. continuously changing their variable prop pitch for a constant optimal rpm).
From his account he believed that he could only get optimal performance from pulsing the rpm, i.e duplicating a CSP with the rpm control being moved back and forth. This seems a little odd, and we must consider that it wasn't actually true. Perhaps if the rookie pilot managed to manually control his rpm at an optimum value like a CSP, he could have overtaken Steinhilper busily pulsing his rpms back and forth.
It is hard to state a good technical reason why the pulsing would have helped. Steinhilper believed that the thrust from the rpm boost could only occur if rpm was dropped again, implying that the extra rpm was high enough to not increase thrust. Perhaps 109 pilots decided it was OK to exceed rpm limits if they only did pulses above the limit, they achieved some extra thrust and speed this way but mistook the reason. Or perhaps a quirk of 109 engine/supercharger/prop design did allow a small performance increment doing this over maintaining rpm at a constant optimal value.
Your explanation of CSP function are correct but not relevant to what Steinhilper described.
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There is another possible explanation as to why pilots were doing this:
http://www.amazon.com/2800-Pratt-Whi.../dp/0768002729
If the hydraulic coupling of the supercharger was generating too much heat then the pilots had to take steps to cool the supercharger down
Pstyle's first post
Quote:
Originally Posted by pstyle
Ulrich Steinhilper, in his auto-biography (chapter 16) , talks about managing the prop-pitch on the early (E3 and E4 variant) 109s during the Battle of Britain. He states that, in order to achieve max climb rate and airspeed (particularly at higher altitudes) one had to constantly increase and decrease the propeller pitch. Increasing the pitch would engage the supercharger, which would be run for a short period (i.e. a second or less?) to force more air into the cylinders, then the pitch would be dropped back down again to disengage the supercharger and convert the power gained into airspeed, and allowing the engine/ supercharger to rest.
Is this effect modelled in the game? Does this constant prop management to engage and disengage the supercharger, allowing for best continued speed?
My experience is that the prop control is modelled to move quite slowly in the 109 in the game. But perhaps the range over which this manipulation needs to occur is quite narrow, just either side of the supercharger threshold?
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the hydraulically coupled supercharger was being "rested" and cooled.