Quote:
Not sure what you are trying to say here...
You do understand you cannot compare propellers at different advance ratio's???
It is not in any way or form valid.
I think this where you are getting confused.
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I can't compare 2 propeller efficiency by using a single propeller curve.
But fw190 advance ratio from 2.54 to 3 when TAS 680km/h to 800km/h. 0.46 is difference.
P47 advance ratio from 2.1 to 2.47 when TAS 680km/h to 800km/h. 0.37 is difference.
if both share same efficiency drop slope above vmax, fw190 lose 5% more than p47. btw, German wide chord prop lose 8% efficiency compared to old narrow design because of 4% Vmax lose.
so if p47 equipped with 4 meter German old narrow prop, p47 should get at least 13% efficiency advantage over fw190a8 new wide chord propeller at 800km/h. furthermore, German wide chord dosen't share same efficiency slope as narrow prop above Vmax because within Vmax wide chord is better and at Vmax wide chord is worse. so wide chord has a steeper drop slope than old narrow chord design.
that is to Say, p47 with old narrow German airfoil 4meter prop could get almost 20% efficiency advantage at 800km/h TAS which is smaller than 466mph IAS.
IMG_1041.JPG
what allied propeller engineers did in WWII is just maintain German WWI standard airfoil performance? of course not.
story becomes complicated when allied developed naca16 and paddle wide chord propeller.
1944 early, both German and allied began to use wide chord airfoil in fighters:fw190a8 and p47d-25
with wide chord design,German get better climbe and turn performance, so was allied.
http://www.368thfightergroup.com/P-47-R2800.html
p47 got more than 10% climbe rate due to wide chord paddle propeller.
It is noticed that p47 propeller is so big that tip Mach too high, above 1 Mach, if you reduce rpm from 2700 to 2520(bigger advance ratio),you'll get 6% more efficiency at 800km/h. But that dosen't mean fw190 could get higher efficiency due to higher advance ratio than p47. fw190a8 prop tip Mach is usually less than 1 mach(1 Mach @800km/h). A bit complicated.
http://digital.library.unt.edu/ark:/...dc62616/m1/25/
Question:
1) Do allied wide chord paddle props suffer efficiency lose just like German wide chord cousin at 750-800km/h?
we don't know.
1) 3-blade naca16 is same as 3- blade clarkY at 750-800km/h. So is the 4-blade vs 4-blade compare?
we don't know.
But one fact is very clear: prop efficiency may lead to hundreds of horsepower difference above Vmax, so a simulation game must pay enough attention to detailed efficiency curve. otherwise, a big difference from history is inevitable.