OFMKTO 1.6 for BMS 4.37
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So, Let’s do a bit of physics here
for the AIM120C :
Please refer to this document :
https://zaretto.com/sites/zaretto.com/files/missile-aerodynamic-data/AIM120C5-Performance-Assessment-rev2.pdfThis analysis is very good.
The guy, based on the shape of the missile and the known top speed has estimatedWeight Propellant : 50Kg
Isp : 265
Burn Time : 7.75sEjectedMassperSecond = 50 / 7.75 = 6.45
ThrustPerSec = Gravity * ISP * EjectedMassPerSecond
This gives a thrust per second of (in SI units)ThrustPerSec = 9.8 * 265 * 6.45 = 16750 N/sec
Total THRUST = 16750 * 7.75 = 129 917 N = 29207 Lbs
Actually the guy said he found in
Hazard of Classification of Unite States Military Explosives ans Munitions Revision 14 2009
the real mass beeing 51.26 KgWhich would make in his model :
total THRUST = 133 122 N = 29 928 Lbs
BMS AIM120 Modeling:
Weight : 113 Lbs = 51.25567 Kg
Isp = 238
Burn Time : 7.4875 stotal THRUST = 119 393 N
so that means that BMS model is 12% less impulse than this guys model, however, that does not mean performance is different as comparison of Drag between the missiles needs to be done
All of this is however in the range of th ephysically reasonnable
Now let’s go to your missile:
Weight : 113 Lbs = 51.25567
BurnTime = 99.975
EjectedMassperSecond = 51.25567 / 99.975 = 0.51268total THRUST = 49687 Lbs = 221 008 N
that means your ISP = (221 008 / ( 99.975 * 9.8 * 0.51268)) = 440
You just modeled a fuel that is 51% more efficient that the fuel know for those kind of application , read
Rocket Propulsion Elements George, P, Sutton 2001
this is NO GO
And this is where you realize that without changing drastically the shape of the missile, which means the weight of properllant it can carry, you can’t reach the performances of the marketing guys
i would suggest for the AIM120D to take those values:
Weight : 113 Lbs = 51.25567 Kg
Isp = 260
Burn Time : 7.4875 swhich would mean
Weight of propellant (lbs)
113.00
Motor Impulse (lb-sec)
29358
BRNTIME
5
+0.000000 +0.100000 +0.125000
+7.600000 +7.625000#-----------------------------------------------------
ENGINE THRUST (LBS)
#-----------------------------------------------------
+0.000000 +0.000000 +3921.000000 +3921.000000 +0.000000
Then recalculate with MDM the corresponding DZL tables
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PLEASE : you reall need to ask questions before changing data !
*maxspeed 0
You need to set up this value to the top value MDM will give you else you screw the DZL computation
“deployableWingsTime 1”
didnt know the AIM120D had wings ?
“miniaerorange 0”
With this value set to 0 , the dynamic DZL computatation is wrong
"loftTableFilename "
The file name beeing empty, the AIM120 Loft data is not loaded at all
SmallFighterPitbull 20
FighterPitbull 22
BomberPitbull 25
HighAspectSmallFighterHusky 24
HighAspectFighterHusky 27
HighAspectBomberHusky 32WTF ??? pitbull range at 22 NM ??? HUSKY @ 27 NM are your kidding ? where did you find those information ?
are you aware that the AIM120 radar as defined in the DB is likely unable to catch the targets with a RCS1 at those distances ?
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Guys i understand that this mod is made with Passion and dedication ,
i’s good to have
But you cannot do things like this, i can’t speak for the BMS team, but personnaly i can’t agree to see BMS moded like this.
PLease ask questions , and listen to the guys who know , that’s the best way to learn
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@Mav-jp woooow i mean woooow dude your window of knowledge is great and vast! thanks for the info and feedback you provided️
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@Mav-jp dude i believe OFM devs sure should use the help of guys like you to improve OFM!
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@Mav-jp i have a question.
what do you think about meteor missile model? do you think meteor is unrealistic too? -
OkAy
Another important thing :
DZL data tables must be computed by MDM , this is the only way to compute them.
Everytime you modify the aero or thrust parameters, you must run MDM again to compute the DZL tables.
Keep in mind that those tables are set up for a STATIC target (and therefore cannot be estimated in game).
Please find here what i would do if i had to guestimate AIM120D
https://mega.nz/file/jhkS2IBI#BXFP2dnRUs7XZCbXZHepmBJQgebiLs4fe9br0ezpk90
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@Mav-jp i hope OFM developers read your comments…
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@pgk007 yep i saw that and it made me thinking about it too…
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@farazparsa said in OFMKTO 1.6 for BMS 4.37:
@Mav-jp i have a question.
what do you think about meteor missile model? do you think meteor is unrealistic too?The Meteor missile is afaik unchanged compared to the stock version of BMS. As the Meteor uses an entirely different propulsion system a one by one comparison isn’t possible. BMS doesn’t simulate a variable thrust RAMJET motor, so Meteor implementation is essentially a compromise within the given constraints.
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@Scorpion82 thanks for the answer ️
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@farazparsa
I hope someone from OMF will read it and check -
Good Day, All. As the Aim-120D discussion has occurred in a couple of threads, I felt The Mafia Journal thread was a good place to respond.
So, you are invited to https://forum.falcon-bms.com/topic/19270/bms-other-fighters-mafia-bmsofm-journal/760 -
@drtbkj
Then maybe You guys will be able to find few seconds to find who stole wingtip contrails from yours nice theater? -
@Mav-jp said in OFMKTO 1.6 for BMS 4.37:
The guy, based on the shape of the missile and the known top speed has estimated
Weight Propellant : 50Kg
Isp : 265
Burn Time : 7.75s
EjectedMassperSecond = 50 / 7.75 = 6.45
ThrustPerSec = Gravity * ISP * EjectedMassPerSecond
This gives a thrust per second of (in SI units)
ThrustPerSec = 9.8 * 265 * 6.45 = 16750 N/sec
Total THRUST = 16750 * 7.75 = 129 917 N = 29207 Lbs
Actually the guy said he found in
Hazard of Classification of Unite States Military Explosives ans Munitions Revision 14 2009
the real mass beeing 51.26 Kg
Which would make in his model :
total THRUST = 133 122 N = 29 928 Lbsasis
Isp = 265, which he took as a basis, very optimistic.
According to information from available sources, for different fuels, the range (Isp) will be something like this:
(For reduced smoke engines, the average ISP be ~255)
Also, for example, the ratio of the engine impulse and time, depending on the type of rocket engine (forms of fuel charge and the laws of their combustion).
@Mav-jp said in OFMKTO 1.6 for BMS 4.37:
Actually the guy said he found in
Hazard of Classification of Unite States Military Explosives ans Munitions Revision 14 2009A good document, about 10 years ago, thanks to this document, it was possible to put in relative order what was happening with the missiles in the ED DСS (Lockon).
True, it turned out at the same time that if we substitute the missiles from the ED, the impulse of the engines and the drag and lift coefficients are close to the real one. then everything becomes very bad with rockets, but, it was rather already connected with game modeling of the density of the atmosphere (external environment) in which these rockets flew.
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@pgk007 Hi, I’m not sure I get your meaning
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@SpbGoro said in OFMKTO 1.6 for BMS 4.37:
@Mav-jp said in OFMKTO 1.6 for BMS 4.37:
The guy, based on the shape of the missile and the known top speed has estimated
Weight Propellant : 50Kg
Isp : 265
Burn Time : 7.75s
EjectedMassperSecond = 50 / 7.75 = 6.45
ThrustPerSec = Gravity * ISP * EjectedMassPerSecond
This gives a thrust per second of (in SI units)
ThrustPerSec = 9.8 * 265 * 6.45 = 16750 N/sec
Total THRUST = 16750 * 7.75 = 129 917 N = 29207 Lbs
Actually the guy said he found in
Hazard of Classification of Unite States Military Explosives ans Munitions Revision 14 2009
the real mass beeing 51.26 Kg
Which would make in his model :
total THRUST = 133 122 N = 29 928 Lbsasis
Isp = 265, which he took as a basis, very optimistic.
According to information from available sources, for different fuels, the range (Isp) will be something like this:
(For reduced smoke engines, the average ISP be ~255)
Also, for example, the ratio of the engine impulse and time, depending on the type of rocket engine (forms of fuel charge and the laws of their combustion).
@Mav-jp said in OFMKTO 1.6 for BMS 4.37:
Actually the guy said he found in
Hazard of Classification of Unite States Military Explosives ans Munitions Revision 14 2009A good document, about 10 years ago, thanks to this document, it was possible to put in relative order what was happening with the missiles in the ED DСS (Lockon).
True, it turned out at the same time that if we substitute the missiles from the ED, the impulse of the engines and the drag and lift coefficients are close to the real one. then everything becomes very bad with rockets, but, it was rather already connected with game modeling of the density of the atmosphere (external environment) in which these rockets flew.
Yeh we took 238 in BMs modeling
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@Mav-jp Hey mav, i am extremely interested to see your estimations on the S-400. I have a hard time buying how a missile not particularly larger than that of the SA-10 and SA-20 can have those insane advertised ranges. Public info for sa-10 = 50nm, sa-20 = 100nm, sa-21 = 200nm. Thoughts? Sure, electronics got lighter since the 80’s, making the weapon lighter. Sure, rocket fuel might have gotten a bit better (has it?) But 300% increase in max range from sa-10 to sa-21??
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@Master-Yoda I think you should have stopped at “advertised”… People lie to sell…
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@MaxWaldorf True. Still, i wanna see a more scientific estimation from a knowledgeable person, ballpark figures are good enough for us civies.