Propeller and Performance Adjustments
Hello Folks!
Further research has revealed that the 2-blade propellers on the earler
Ju-52 were 9.5 ft in diameter, and on the flight model, this parameter
adjustment increased RPM a little. (The Condor had 9.7 ft propellers).
Then, aiming for 165 mph with 725 Hp at 2050 RPM, slight adjustments
on the propeller power coefficient table for the curves J=0.6, 0.8 and 1.0,
as well as other very small changes in Drag and Torque, finally gave very
close results:
S.L. horizontal speed at full throttle is 165.2 mph, with 726 Hp at 2046 RPM,
which is quite pleasing, and can be quite acceptable, at least for the moment.
Now that I have a reasonably well-behaving three-engined airfile, I can start
making the AF99 cardboard mock-up model.
Update:
Hello Smilo,
Attached with this post is the new CFS1 .air file, for any trials or experiments
you may wish. Itīs called Ju52-3m.air, and will have to be re-named it to fit an
existing FS98 model that you may be experimenting with at the moment.
Cheers,
Aleatorylamp.
1 Attachment(s)
Cockpit area, main gear and inner wing
Hello Folks,
In the last 3 days Iīve been working on the cockpit area.
Initially the windows were transparent, but it was taking a long time to fight all the bleeds,
and only with limited success, so to get ahead a bit again, for the time being at least, Iīve
made it opaque.
In the meanwhile Iīve also improved the landing gear struts, and the wing-root and innerwing are 3D now.
You can see how the outer wing is still 2D. I havenīt adjusted the provisional engine nacelle shape very well - itīs only for some kind of visual reference anyway.
Hereīs some new screenshots of the progress.
Cheers,
Aleatorylamp
Ju-52/3m Drawings, Engines and Propellers
Hello Ivan,
I found the Wikipedia ones quite good and Iīm using those.
For the Spanish version with the bigger engine cowl Iīm using photos.
I wouldnīt mind looking at the russian site - Iīll see if I can find it, perhaps the drawings are even better!
I can see from different sources that there is a lot of generalization as regards performance, and they state the same for all motorizations, which is absurd, of course.
165 mph S.L. max is fine for the BMW-132-A3 725 Hp motorization, but not for later models that had upto 850 hp engines. (I am not including the few earlier versions with Hornet engines).
However, one or two sites give better details here, and performance seems to go up to 170 and 175 mph for the Spanish ENMA BETA 750 and 775 Hp versions, and upto 183 mph for the 830 Hp BMW-132-T2 version. My calculation for a BMW-132-Z 850 Hp engined version would be 187 mph.
Another thing has to do with one of my 2 favourite propellers: The 2-speed 2-position propeller. (The other one is the wooden 16-degree pitch Sensenich one!)
It is obvious that the 2-pitch prop was being used on early models, from the 725 Hp ones, through to the Spanish engines, and perhaps even upto the BMW-132-L 800 Hp BMW engined.
After that, Iīd wager all later models would have had the 3-blade CV props.
My trials with .air files and propeller tables would corroborate that.
Anyway, I would indeed welcome any help or suggestions from you if you like!
Cheers,
Aleatorylamp
3 Attachment(s)
Industrial Sound & Drawings
Hello Aleatorylamp, Smilo,
That sound question is interesting. I have never really noticed the sound effects because normally I have the sound turned down VERY low.
One has to do that when all the other folks in the house are sleeping and one is still playing on the simulator!
If you want me to look at the CFS AIR files and where the issue might be, please email me a pair of AIR files for FS98 and CFS.
I have actually been wondering about how to generate some other sound files such as for a Napier Sabre engine or the starting sounds for an inertial starter or Coffman Cartridge starter, but those ideas are way low on the list. The Ki 61 needs to get finished first.
Regarding Drawing from Wikipedia....
In general, the line quality is pretty good, but the accuracy of those drawings is always suspect in my opinion.
I have found in the past that the artists often invent details and shapes that were not in the original aircraft.
Here are a couple drawings with some useful dimensions so that you do not need to scale off the Wikipedia image.
Is there a particular model designation of the Ju 52/3m that you are building? Apparently there are a lot of variants.
- Ivan.