Quote:
Originally Posted by MadBlaster
interesting. I'm suggesting that at point A with a canister of mw50 on board that the 190 guy trade high rpms and prop efficiency while TAS is low, for thrust 'instantaneously' (limited by rate of change of the blade angle) by over-riding auto prop pitch (slower response). The prop would not be spinning at 1350 rpm. It has a load on now, so is spinning at say the lower end of the power curve for the bmw engine, guesstimate, 1050 rpm. Point C for 190 is irrelevant because dive speed limitations are upon him. The race is for point B. How long does it take for p47 turbo to spool up??? How long does it take to get power from mw50???
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1) German tried MW50 on BMW801 but finally gave up. It's said that MW50 is harmful to BMW801's piston. 1945 version Dora's Jumo213A(liquid cooled) was equipped with MW50. However, 20000ft(6000m) is probably above 190's FTH, so there is little benifit from WEP.
At "A" point, if fw190 uses 1050rpm propeller, tip rotating speed is 165m/s, TAS is 126m/s, Mach number=207/310=0.67. Quite below 0.9mach. But I'd to say the propeller's has a certain optimised rpm, if you use full 100% throttle while reducing propeller's rpm incorrectly, you will lose efficiency. Your propeller probably couldn't absorb engine's output.
2) C point is above fw190's max allowable diving limit?
3)I don't know how long does it take for p47 turbo to spool up. I guess it's several seconds?
4)Last but not least, Do you have the information of Dora's 41276.16 V propeller? The size of it, the reduction ratio etc. As we all known before 4.11m, Dora flys so fast.