Me110G-2, Me410 and Mosquito Mk.VI maximum speeds.

[RTHolmes]

yup, the drag area or reference area is the A in AC_d above.

considering the dimensions of the 410 and mossie and their frontal projections, A_mossie and A₄₁₀ look pretty similar to me, the mossie is a little bigger but a little less chunky.

I still reckon the difference in C_d values is the biggest factor here.

[Karnak]

Is it possible the power output of the German engines is being reported as higher than it really was?  False claims from manufacturers to the German government were not unknown.  We have performance tests of both aircraft that seem unlikely to have been falsified and power output claims for their respective engines that seem to not be able to be matched to their demonstrated performances.

[moot]

Could the 410's Cd be calculated with small enough error margins by just giving a CAD model to someone with access to one of those CFD virtual tunnel apps?

[W7LPNRICK]

Cd? Co-efficiency of Drag?

[Wmaker]

Could the 410's Cd be calculated with small enough error margins by just giving a CAD model to someone with access to one of those CFD virtual tunnel apps?

Basically, yes. My experience with CFD software is limited to two hour excercise but I'm sure there shouldn't be much file-format conflicts in general considering that analysis of this kind of nature is done all the time in the industry. It would obviously have to be rather accurate model to gain accurate results and takes quite a time to compute depending on the computer.

Something you might find interesting: http://www.hobbybokhandeln.se/j22/CFD.htm

[Krusty]

I approve of Moot's bump 

[moot]

I'm willing to do the model if anyone can pass it on to someone who'll run it thru CFD..

Thanks WMaker, that's one of the things I was looking for.
... That's great!.. That software looks free to the US public... Bummer.. It's only for Mac.  But at least there ought to be someone who can use it with the model one of us would make.

Guess I'll do it on 3DSMax.  Seems like a safe bet format wise.. ?

[Charge]

http://www.public.iastate.edu/~akmitra/aero361/design_web/airfoil_usage.htm

Messerschmitt Me 410, NACA 23018-636.5, NACA 23010-636.5

Might be of some help...

Can you guys use an existing model? Eg. from IL-2? I'm sure the conversion alone will be a hefty job to do. Then again could be easier to do one from scratch...

-C+

[RTHolmes]

thats a pretty massive modelling task to get any meaningful numbers out of it.

[moot]

RTHolmes I haven't started yet, but if you can definitely say it's not feasible, let me know now

It seems the second Me 410 book by Petrick has a clear picture of the plane that was modified for high altitude interception: no radio mast and no barbettes.  Maybe some valuable clues can be found if its performance is mentioned somewhere.  A better pic than this one:


Will have to look into Il2 game models..

[Wmaker]

RTHolmes I haven't started yet, but if you can definitely say it's not feasible, let me know now

I can't say I speak from experience or even with much knowledge...take it what it's worth...but...

...if the numbers that come out from the CFD-analysis are within 20-30% of the calculated numbers you really haven't solved much IMO. Numbers from the theoretic, smooth 3D-model will always be better than reality. Although I'm sure that just like in any mechanical engineering field there's plethora of multipliers/coefficients that can be used to account for manufacturing imperfections and to create safety marginals between normal stresses and failure of a structure. Ie. I'm sure there are surface roughness multiplyers etc. to account for how a real manufactured aircraft would perform but setting these multiplyers is obviously kind of "guess work" in this situation. Obviously there aren't any "black and white" answers to be found as every aircraft is an individual...especially 60 odd years ago.

What goes without saying is that it would be an awesome learning experience and you would come out of it knowing helluva lot more than you know now. For that alone it would be more than worth it but IMO you shoudn't be doing it for the results alone as you might be dissapointed with the lack of conclusive results.

[RTHolmes]

^ thats what I reckon. getting the 3D models detailed enough will be a huge task, if its even possible. small tweaks to the shape can yield large differences in aero effects.

[FLS]

I think the short answer is that the Mossie was designed to be fast and that was the primary design criteria to the point where it was considered too radical and initially rejected. Since drag is exponential small differences in Cd mean bigger speed differences  than similar differences in thrust.

[moot]

I only have enough time to make a model about as good as enthusiast blueprints and other references will allow.  I won't have time to get into the CFD (don't know where to find a CFD app yet) till late this summer.

[morfiend]

I think the short answer is that the Mossie was designed to be fast and that was the primary design criteria to the point where it was considered too radical and initially rejected. Since drag is exponential small differences in Cd mean bigger speed differences  than similar differences in thrust.

  I would agree,look at the various speeds found on the mossie of the same model! I recall reading about a paint job that took 8,10 mph off the airframe.The mossie being wood could be sanded to a fine finish that a rivited metal plane just couldn't attain.

  Now I have a question,where would the effects of this drag be felt more,at low alts or at high alts?


     


  PS: I'm not sure of the answer myself,so I'm not trying to be a smart a.....