3 Attachment(s)
Focke Wulf Fw200-A Condor
Hello Folks,
Well, as it turns out, at the end this project will need an own thread, because there are a couple of things that need attention before a CFS1 upload can be undertaken:
1) - Flight Dynamics:
Although the FS98 .air file is quite good, itīs for FS98, so it doesnīt take advantage of CFS1īs supercharger capacity. Itīs in the making, and there may be some issues regarding the power curve for the 720 Hp @ 2050 RPM BMW 132-G1 engines with their single-speed superchargers, that need tweaking.
Update:
It appears that max. speed was 226 mph (at S.L.? dunno...), and apparently the Maximum Manifold presure of 1.2 ATA was maintained upto 6000 ft. Doing it this way in the .air file, there are unwanted peaks of almost 250 mph at 6000 ft and 9000 ft, even reducing the 226 mph at S.L. to 221 mph.
However, using a "similar" criteria of maintaining 720 Hp instead of 1.2 ATA upto 6000 ft, then the peaks come down by 6 mph, but it is still 14 or 16 mph too high. So, itīs still on the drawing board...
2) - Virtual Cockpit:
AF99 didnīt have enough parts to make a virtual cockpit, so it wasnīt included for SF98. Given the good FS98 panel by Pegasus Design, this was a viable option. However, not so for CFS1, because with SCASM, a virtual cockpit can be made, and it will be a good idea to include one. It will most likely have to be a call in the usual position of the listing for VCockpits, to some extra parts placed at the end, similar to the Zeppelin Staaken SCASMing.
3) - Panel:
The Pegasus Design Panel is very good for FS98, but needs different instruments for CFS1. Also, I donīt know if it will be very useful having 2/3 of the cockpit shown - it makes the cross-hairs seem off centre. Hence, for CFS1, it may be more useful to have a complete and centred panel. As right hand side instruments are repeated, possibly nav. and com. instruments will be handy there. So, while Iīm at it, Iīm making the panel bitmap too. Hereīs a screenshot of the provisional panel - still including the Beckwith gauge (dig Ivanīs new gauges!).
In consequence, this project canīt be a direct FS98 upload into CFS1, but a CFS1 adaptation, and will require a little work before it will see the light of day. Iīm sure itīs better to do it better than to leave it go as it is...
Cheers,
Aleatorylamp
Propeller Table 511 and 512 surgery?
Hello again, Ivan!
First I established the correct 226.8 mph performance at S.L. for the "new" older gearbox-less engine and smaller prop.
Then at 6000 ft I got an excessively high performance - 255 mph instead of 242 mph, which could almost be corrected by pulling down the propeller pitch levers all the way. I got 243 mph.
So, after two cups of tea I had a look into Propeller tables 511 and 512 trying to see where the differences were for the P51d and the P38, for example, and was no wiser after that. Some places in the table are identical and others different, and it means nothing to me.
Then, after another cup of tea I had a look into the AAM Graph depiction of these two tables, of which I made screenshots.
Unfortunately I am still none the wiser.
However: Manually, all the lines in the graph can be selected and their individual positions can be moved up or down by mouse.
In general, the idea you are putting forward is to try to manipulate the graphs to perhaps be able to adjust correct performance at altitude.
So here comes my stupid question and conjecture:
Which parts of the graphs would need intervention, and in which direction?
In theory, at altitude and with speed, the propeller is at a greater angle, and this angle would have to be made less powerful, but how? My conjecture would be to try and lower the 20, 25, 30, 35, 40 and 45 degree graph lines a bit? Does this make sense?
Update: Iīve just done this, and it got worse - the opposite happened:
S.L. performance went UP from 226.8 to 241 mph and 6000 ft performance went UP from 255 to 261 mph.
So obviously it wasnīt the thing to do, was it? Hmmmm.... but, Iīm learning...
NOTE: The middle screenshot is the modified table 512. The one on the right is the original, unmodified one.
Update 2: The puzzle unfolds with increased complication:
Raising instead of lowering the graph lines obviously has the opposite effect, lowering performance including at S.L.
However, if the 20-degree graph line is left untouched, it reduces speed more at altitude and not so much at S.L.
Looking closely at the Beckwith Gauge, the propeller advance ratio range for full power depending on altitude is rather small - between 20 and 22 degrees or so.
For cruise speeds, advance ratios seems to be around 19 degrees. To adjust throttle settings here would require changing the 15 and the 20 degree line too.. But this will also affect Take-off Power and S.L. Performance, wonīt it?
I realize that you have not yet concluded your own experiments on the subject, but perhaps there is a general idea that I could try and follow. ...Maybe Iīm letting myself in for something quite out of my reach.
Thank you again for your continued coaching, and in advance for your possible views on this difficult subject.
Cheers,
Aleatorylamp
The comprehensive list of collected data:
Hello Ivan,
Iīve had enough time (just about) to do my homework:
Prop advance ratios, as per RPM, Hp, Thrust and speed
For max. Speed at S.L.Takeoff:
15.0, 2024 RPM 228 hp _869 thrust 44 mph
25.0, 2028 RPM 505 hp 1299 thrust 88 mph
31.2, 2025 RPM 719 hp 1405 thrust 128 mph
33.0, 2026 RPM 721 hp 1231 thrust 169.2 mph
34.5, 2025 RPM 720 hp 1231 thrust 196.2 mph
For max. speed at different Altitudes:
_300 ft : 36.1, 2025 rpm, 720 hp,1010 thr, 226.8 mph
5000 ft : 38.7, 2024 rpm, 751 hp, 978 thr, 240.2 mph
5900 ft : 39.2, 2024 rpm, 756 hp, 972 thr, 242.9 mph
7000 ft : 39.2, 2024 rpm, 726 hp, 934 thr, 243.0 mph
8000 ft : 39.1, 2024 rpm, 701 hp, 904 thr, 242.5 mph
9800 ft : 38.9, 2024 rpm, 654 hp, 848 thr, 241.8 mph
12500 ft: 38.5, 2024 rpm, 583 hp, 760 thr, 240.6 mph
15000 ft: 38.2, 2024 rpm, 524 hp, 689 thr, 239.1 mph
19000 ft: 37.5, 2024 rpm, 439 hp, 587 thr, 235.0 mph
...and one cruise speed. Should more be required, they will be done!
300 ft Cruise: 31.2, 2024 rpm, 480 hp, 774 thrust, 201.2 mph
With this cool-looking list, I bet thereīs going to be an equally cool-looking list of formulae to be applied, but, before I can think any further, I need some more tea, and some other "thangs" have to get done this afternoon.
Cheers,
Aleatorylamp