tavarish palkovnik

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It would be better if you make one your own, you can start with simplified model and then step by step upgrade it with details like erosions and propellant initial temperature and involving more and more variables. When you make first one and learn basics it will be much easier to build around it. I don't have drag and lift coefficient data for Phoenix, I use estimated ones when making external ballistics with Phoenix, but that also can be calculated and to be quite precise

@Lans Missile launch weight is 1010,3 lb (458,5 kg) and burnout weight is 639,8 lb (290,5 kg) so it is 168kg of fuel more or less. There is some of difference most likely in igniter and ablative coating and gasgenerator but for calculation it can be taken as 168kg of fuel. Loaded motor itself is 465,2 lb (211 kg) so it 1,26 ratio and motor although it is steel construction due to relativelly low pressure and quality steel used for case is as light as it is. Case wall thickness is only 1,092 mm making total weight of case just 14,9 kg Yes, this motor is degressive, grain with two slots in shape as it is simply is with degressive burning surface. That's why they said average thrust is 5000 to 1000 lbf (22269-4454 N) and this most likely resulted with confusion and with sometimes calling this motor as dual-thrust motor what it isn't actually in full manner. This I made in just simple Excel with calculating integral of all these parameters which you can find in that paper, and just few of parameters are constant values (density of propellant for example or ambient pressure) and rest of it are variables for integral. Depending of integral step results are more precise. Just loop of numbers, burning surface+burning rate value -> chamber pressure -> thrust -> new burning surface and new burning rate value gives new chamber pressure and new thrust and in the circle until all fuel burned out If you like this and having interest in this amusing wasting of free time I'm willing to share some time of mine

@Lans Is it used in DCS I don't know, I've offered them this model but did they accept it I don't know. Most probably they didn't because it would crash down established ''theory'' that Mk47 and Mk60 give different output what is totally unreal and unfeasible for normal operation of missile with exchangeable motors. And unfortunately this ''theory'' spread out all over the internet like a flood. This is just my reconstruction of this motor based on long time digging and searching for valid information and finally it's ended with this, and I'm very sure this is it. Just some of literature that help a lot: ''Handbook Naval Air Launched Guided Missiles'' which gives general info about dimensions and masses ''Solid Rocket Motor Nozzles by NASA'' which gave a lot, what motor gives as thrust, how long it works, what is max pressure, very important it gave complete nozzle geometry and characteristics of throat insert, type of propellant etc etc and at the end paperwork ''Burn rate consideration in solid rocket motor performance prediction'' like cream on cake which finally gave how propellant grain in Mk47 is actually configurated and some for calculation important extra data. And when merge all that with basic stuffs about rocket motor propulsion you got this. Geometry of Mk47 Mod.0 gives exactly what is described for Mk60 Mod.0 and for me there is no doubt whatsoever it was like that in real...no matter what internet says

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Grid fins are actually magnificent, those surfaces have some disadvantages in some segments but also huge advantages in others. The ones taking only one side of medal, don’t know anything about ballistic theorems and just blowing bubbles. Here on this forum, as well as in some others, so many talks about drag, and about everything else contributing flight paths, just random guessing Sorry but I got such feeling by reading these threads about rockets, motors etc

@tripod3 Good luck in finding answers how Oka actually flew. You will need it , I’ve tried to figure it out and than simply gave up. Both Elbrus and Oka had controllable motors, controllable in means of switching it off depending of targeting distance but while Elbrus actually flew in ballistic trajectory this Oka monster did not. And…internet is full of contradictions when describing Oka’s characteristics, maybe the most of all rockets

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I’m looking for pressure-time diagram of Mk36 Mod.5 motor (Sidewinder 1C AIM-9D) or Mk50 Mod.0 (Chaparral). Or of any other Mk36 in 6-points star configuration, preferably with composite propellant. So if someone has it, it would be appreciated. There are few of such kind on dtic.mil when motor pulsing were performed in past, seams like similar but always something missing or simply is not what real Sidewinder motor should looks like

I’m looking for pressure-time diagram of Mk36 Mod.5 motor (Sidewinder 1C AIM-9D) or Mk50 Mod.0 (Chaparral). Or of any other Mk36 in 6-points star configuration, preferably with composite propellant. So if someone has it, it would be appreciated. There are few of such kind on dtic.mil when motor pulsing were performed in past, seams like similar but always something missing or simply is not what real Sidewinder motor should looks like

@draconus Look mate, I saw so many absurds here so that lot of things is coming on my mind, even this what you wrote last. After motor of R-27ER this one is of biggest interest of mine, and I put lot of work and time in finding answers. Perhaps they had some documents but it is question if they read it correctly. If you followed all what we wrote about it in sequences of finding answers how it works, you could see how sometimes numbers and all what is behind it can be tricky. One eventual case, what if they managed to find or get from somewhere pressure or thrust vs time curves for AIM-54 and one was for high and other for low temperature range, and somehow they took it as two different motors. Everything is possible, however slotted tube grain inside of Mk47 when processed gives exactly what is given to Mk60. I would really like to have comments of these chiefs which worked this out, comments regarding my results, that would be nice to hear and very much appreciated. Also even more I would appreciate if could get some words how Mk47 and Mk60 became different to them.

There is no single one relevant document and/or literature saying that Mk47 Mod.0 and Mk60 Mod.0 (even Mk47 Mod.1) have different output characteristics. Only DCS and WT say that. Missiles having same flight control section with all those stuffs inside, gyroscopes, accelerometers, barometers etc etc need to have same source of energy, otherwise dynamic and flight control would be impossible. Just like AIM-7E with two exchangeable motors, Mk38 and Mk52, one is with internal-external burning tube form of grain, other one with 5 point star. But both were giving same. Also AIM-7F with Mk-58 and Mk-65, first one is internal burning tubes with radial slots, while other one is with finocyl and slots in dogbone form but at the end both have same characteristics. That same is and must be case with AIM-54 as well. I made very detail mathematic, taking grain geometry of Mk47 and nozzle geometry of Mk60 and output came as for Mk60 should be. Only what is missing is to find and see how grain in Mk60 looks like. Perhaps slotted tube (two slots) like in Mk47 perhaps something else but it must give same result.

In addition after motor, to see what should be final score, what should be final velocity if motor gives this what it is gives. One example easy to calculate, horizontal flight, max altitude and max launch speed T.pdf Looks fair and square, total drag impulse is 137500 Ns what is 30% of thrust impulse, total additional speed 840m/s what seems as reasonable for this altitude By the way...with same model and if thrust force would be constant 13595 N for 27 seconds, final velocity came out as 1265m/s or 4,29M

A little bit more of mathematic ... AIM-54 motor.pdf I don't know what public available data were used, either by NASA or here. All I know NASA in their own handbook (Solid Rocket Motor Nozzles, page 10) gave characteristics of this motor, in very much details. Together with configuration of grain these numbers are precisely confirmed as you could find on previous page Depending of temperature motor works from 20 to 30 seconds √ Maximal chamber pressure from 1000 to 700 psi (from 69 to 48 bar) √ Average thrust from 5000 to 1000 lbf (from 22269 to 4454 N) √ Only maximal pressure of 69 bar I've got a bit higher, all right, maybe it is not +70degC but +60degC or +65degC as upper limit. When have all this, and when have basic theory about rocket propulsion everything can be calculated, it means easily and indisputably we can have thrust values of this motor in function of altitude. Of course, this is one pair of aces, the other pair of aces is that drag coefficient significantly increase with altitude because of friction, but this motor compared to some others gives up there quite much then friction takes.

As promissed, here it is pk AIM-54.pdf It is free to use, if you once decide to make modification OK, if not again OK, I do not play this game after all so it will not bother me. But what bothers me is that most of googling about this motor is related to DSC and WT, and data coming from there, data which are simply wrong. Tomorrow when and if AI takes control, hopefully never, it will be spectacular. It is an order to share it here, after all, here in all these pages huge portion is done, geometrical features of motor and concept and geometry of grain raised up, and that made half of work done. Rest is just merging of it with existing and available output data about this motor, by using common theory about rocket propulsion with various data related to that time, and here it is. For any question about any of these steps, data, formulas, whatever, I'm available

Tomorrow or in coming days I will share you complete calculations about this motor, it is actually already done after some time of investigation, base is done and I will just add some finesses like erosion of throat and temperature sensitivity coefficients to see how it works at min and max temperature. No wish whatsoever to implement it in this game, just want to write something what is different to what circulates on the internet about this motor (motors) … just want to make it correct

It hasn’t been “independently verified” so it doesn’t count

No it wouldn't because specific impulse is very fluid value. In such hypothetical (impossible) case where atmosphere influence by chocking motor but in same time does not produce drag, missile would reach maximum 3 M Take a look page in front, those diagrams how specific impulse change with chamber pressure, nozzle expansion ratio and altitude. Phoenix motor is with nozzle ratio 18,5 and average pressure is 700psi so easily case with nozzle ratio 20 and pressure 750psi can be used. Down there specific impulse is 220s (I've got 216s in calculation) -> So down there impulse should not be 2490 Ns/kg but 2158 Ns/kg (220*9,81) and together with ln(447/279) it makes 1017m/s or 3M (speed of sound at sea level is 340,28m/s) Of course this combination without drag at sea level is just empty talks, but up there where atmosphere is rear, where this awkward motor gives high impulse (range of 270-275s) things are significantly different

Hmm, much more documents talk about velocity above 4M. Luckily professor Tsiolkovsky left us theorem which still holds undisputed -> v=Isp*ln(m0/m1) One documented sample, rocket R-40 (MiG-25) of similar exterior and drag respectively. It says maximal velocity missile itself generates depending on altitude and launch speed is 540 to 720m/s. Of course lower level of stratosphere (above tropopause) should be considered as altitude for maximal, and there speed of sound is 295m/s what will be needed to convert it to Mach number. R-40 is with starting weight of 470kg, propellant weight is 118kg…ln(470/352)*Isp=720 … Isp=2490 Ns/kg This is specific impulse up there after real one is degraded by drag loses. Motor of R-40 works on much higher pressure then one of AIM-54, pressure increases specific impulse, but motor of AIM-54 has high expansion ratio of nozzle which also increases impulse on altitude and turn it and twist it all around…that could be like deuce in tennis. Why not to consider same specific impulse for AIM-54 … -> ln(447/279)*2490=1174m/s … -> 1174/295=3,98 M … maximal self generated velocity of missile. Information on internet often can be quite vague