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Missile aerodynamics simulator

Dilbert

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Maybe this will be interesting for someone,

Some time ago I became finally so frustrated with meaningless comparisons of air-to-air missile ranges found on the web (and even in some books and journals), that I decided to program my own aerodynamic simulator for making own comparisons at different launch airspeeds, altitudes, etc. I don't have a solid confirmation that the results are accurate, but I've found it educational and somewhat useful for rough comparative purposes, and had some great discussions out of it on other forums:

http://www.ecf.utoronto.ca/~pavacic/missiles/minizap.zip
 

Dilbert

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The specs (weight, dimensions etc.) have very little guesswork, around 90% is based on verifiable unclassified data.

The errors result from (a) trajectory model, since this is mostly guesswork especially for loft, and (b) drag coefficient, since no two references that I used seem to agree how best to calculate this exactly. :(

Although it probably won't give absolute range/speed accurately, I think it's still quite handy for comparison purposes, which missile flies farther/faster/higher than the other, since errors (a) and (b) should affect two compared models more or less the same.
 

mrdetonator

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nice ;) yesterday I was playing with that a little and compared various missiles with my sources. May I ask where did you get those numbers like propelant mass, specific impulse, burn time especially of those russian missiles if you said a 90% of it isn`t guess work? Just for comparing your simulation, here is a nomograph for calculation of maximal launch distance of R-13M.
Vs-speed of aircraft (km/h)
Vsbl-closure speed to the target(km/h)
D-launch distance (km)
Dmax-maximal launch distance, corrected (km)
H-altitude(km)
 

Dilbert

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Very interesting, thanks! I'll study it.

Some data for Russian missiles came from modern Russian-language journals (there was a good series in M-Hobby in recent years), but the best was real technical manual data provided by Eastern European source.
 

Dilbert

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Interesting chart.

Would I be correct to guess that R-13 can be used only in a tail-chase from the target's six o'clock position, and only when the shooter is flying 1000 km/h or faster?
 

mrdetonator

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The exact R-13M launch limits are following:
-usable outside clouds, in night and day and sun angle min. 30deg
-aircraft minimal speed 550km/h, M>=0,8 in altitude max. 17500m, max. M<1.8
-usable altitude 50-15000m
-missile launch zone in rear aspect, min. 0.9km, max. 15km
-at racurses: from 0/4 to 3/4
-aircraft engine regime: from idle to afterburner
-max.allow. g-load limit when launch: 3.7

No closure speed limitations at all. Therefore, I think the graph is only recounting some "optimalized" intercept speeds. If you draw parallel lines on the other side, e.g. -100km/h, -200km/h,....you`ll get shorter launch distance, and hit "zero" distance at some point.
 

tomcat1974

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"at racurses: from 0/4 to 3/4 "
Does that means that R-13M is capable of head on firring ?
Thanx
 

Schorsch

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Dilbert said:
Maybe this will be interesting for someone,

Some time ago I became finally so frustrated with meaningless comparisons of air-to-air missile ranges found on the web (and even in some books and journals), that I decided to program my own aerodynamic simulator for making own comparisons at different launch airspeeds, altitudes, etc. I don't have a solid confirmation that the results are accurate, but I've found it educational and somewhat useful for rough comparative purposes, and had some great discussions out of it on other forums:

http://www.ecf.utoronto.ca/~pavacic/missiles/minizap.zip

You programmed a great tool. Actually I recently had a similar problem and was frustrated about useless data on maximum vertical speed and climb performance. I wrote myself a little simulator. Weakest point is the drag model in transonic region and drag penalty of external stors. Additionally all information on low-bypass engine behaviour of Mach and altitude are welcome.
I just downloaded the F-18 manual and will see if I can drive any conclusion about it's drag from it.
 

Mercurius Cantabrigiensis

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A interesting tool. But the missile data seems to be 'hard-wired' into the EXE file.

I can see how to get the program to write a datafile for the missile being simulated, but is there any way of getting the program to save and reload missile parameters devised by the user?
 

jc65

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Hi, Excellent simulator, thanks for sharing.

I used to test ground-air missiles like the VT-1 (crotale ng) and 57e6e (Pantsir), and got the results published by the manufacturers but using skin drag factor of between 0.8 and 0.9.

vt-1: http://www.thalesgroup.com/Portfolio/Documents/VT1_brochure_pdf/

57e6e dart: 32 kg, 1300 m/s, 90mm diameter.
 

totoro

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i can't get realistic figures for ground launched missiles, though. does the program simulate those, since it includes a template for patriot and s300?


I always get unrealistically high engagement ceilings as possible, even for short ranged missiles like aim-9 and such.


Also, i dont understand if the templates for various missiles already include a fear deal of manouvering through which quite a bit of energy is lost? Is there a way to simulate pure maximum ballistic trajectory (even if depressed) ranges for any given missile?
 

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