automatic e-m diagram generation tool

[Zigrat]

hi guys,

here is a much improved spreadsheet i wrote. it will generate e-m diagrams for any plane based on a few numbers you input. these diagrams will not be 100% correct because they are generalized, but they will give you a pretty good idea of how the specified airplane will fly, and what speed range it reaches its max turnrate in.

on teh chart it generates, the red line is the aerodynamic restriction of your airplane, and the green line is the sustained restriction (no acceleration or decelleration or change of altitude)

like i said, if this chart says your plane should have a max sustained rate of turn of 24 degrees per second, it might very well be 26! Its not 100% accurate since its generalized. but if the chart says 24 and the game is giving you 36 or something then you know something is fishy  

also please ignore the hp calculations part (part c) thats not working right as of yet, i'll work on that more in the future.


you need excel 97.

-zig
 http://www.iit.edu/~buonmic/airtest3.xls

btw this will be neat because you can put in the aircraft performance at high altitude. it would be interesting if someone did for example a comparison of the spitfire IX and the N1k2 on the deck and at 20,000 ft using this program. i spend like 10 hours getting it to work right (i tried a bunch of stupid approaches like using three dimensional arrays of data and other headaches) so i dont feel like messing with it more right now   but id like to see some result!

[Toad]

Really nice idea!

Thanks for doing all that work.

<S>

[sax]

Thx Zig, great flight tool.

Sax

[Seeker]

Help a dummie!

I see on page with a familiar EM diagram, but no label to tell me which plane, nor anything I recognise as an input box; one sheet with a mass of data (which I sure don't understand!) and two blank sheets....

So in short, how do I use this spread sheet?

<not an experienced excell user>

[Naudet]

Zigrat, how u evaluate this data??

Bye testing certain planes in AH after doing the table?

And how u test turn rate in AH? Are u doing say a 2G turn t 250mph and stop the time for a 360 degree turn?

[Zigrat]

sorry here's some instructions

go to the sheet labeled sheet 1

go to the upper left portionof this sheet

you will see a box that says step a enter aircraft dimension data. youneed to know the aircraft weight (loaded) wingspan and wing area.

then go to step b.

enter the altitude you want information on, the maximum speed of the airplane at that alt, the power of the engine output at that altitude, and teh stall speed at that altitude.

thats all you need. then go to the e-m diagram and it will be drawn for you.

[F4UDOA]

Zigrat,

Great work again.

Do you have anyway of determining performance with flaps, ala the NIK2 or F4U with 2 notches of flap? I know Pyro is working on this for 1.08.

The only problem with determining turn performance is that it is based mostly on 1G stall numbers. For A/C like the F4U, P-51 and P-38 this information is readily available from pilots manuals but many versions of the 109, La5/7, Yak and others this information is not so easily available. If anyone has this data (stall numbers, not AH) please post them. Niklas is the best source of Euro-fighters I have found.

[Zigrat]

well for most planes its not too hard to figure out stall since you can have a good idea of clmax just from knowledge.

all the 190s, f4us, and f6f have the same airfoil and their planforms arent too different. all these airplanes have a clmax of ~1.5

the p51 has a clmax of around 1.4 i think if i remember (not sure) and i would think that the yak and 109 are going to be in the same range - around 1.6 for them i think.

the spitfire and the p38 are significantly higher if i remember, the p38 cuz of its high AR and the fact that the nacelle acts as a boundry layer gate (as on the mig-15) and the spitfire has a nice elliptical planform, i think its clmax is around 1.8.

if you want to know the effect of flaps, do this f4udoa:

put the plane into autoclimb at a specified climb speed  and record the result. use a relatively low (less thab 200) climb speed since this is where you would be using flaps.

then go repeat this climb test, but add in the amount of flaps you want for your test. record the climb rate.

also test the 1g with flap stall speed and enter this into the sheet.

ok once you have done this, adjust the CD0 of the airplane manually (instead of having the program calculate it) until you get the climb speed result that the game gave you.

now the em-diagram will reflect the performance of the airplane with flaps engaged.

be careful not to save your work in the same filename tho since you wil have changed the formulas.

hope this helps, but feel free to ask more questions.

[bloom25]

When I saw EM I thought, "What's Zigrat doing writing an Electromagnetic Field diagram."  

(If you can write one of those up I *might* be interested.   )

Sounds like you spent a lot of time on this Zig, I'm sure quite a few will appreciate that.

[Zigrat]

to answer your question, i found that the use of combat flaps (2 notches) in the p51 serves only to decrease turning radius at max sustained turn by 70 feet, but does not increase turning rate at all. you fly a smaller circle slower, basically

[StSanta]

Hey Bloom, done yer exams yet?

Did ya pass?

Myself, I've got a vacation now  . Passed my exams and am now chilling out  

[F4UDOA]

Zig,

Great idea for finding out what the Cl max is for AH planes. I will test this also.

But what I want to know is this.

IRL a F4U max cl no flap is approx 1.5, with full flap CL max is approx 1.9 (in case Niklas is reading this I know these numbers are with prop installed     ). Also the max flap deflection on a F4U is 50 degrees and there are 5 positions of flap. So what is cl max with 20 degrees (maneuver flap setting) on the F4U and what then is the turn rate radius. I believe that makes the CL max with 2 notches or 20 degrees of flap 1.66. The rest I would ask of you.

This is one of the fixes for 1.08 that Pyro is working on.