tavarish palkovnik

New findings about Mk47 Mod 0 So it is tube with slots after all, it has sense although it can't be recognized on that cross cut photo That is something like this, and of course to have final answer how this motor works (in single or dual mode) number, position and dimensions of slots have to be determinated. Four slots will give nearly continuous burning surface while 6 for example will give booster phase (or better to say a bit regressive process). Photo of cross cut model in better resolution would give all what is needed

All right, I thought there is some description behind every rocket, motor this or that, thrust like that etc. In any case I think this one is simply just wrong. There is no reason not to believe that series 38 and 52 follows each other so Mk38 Mod.3 should be somewhere in line with Mk52 Mod.3 and if AIM-7E-2 is more or less in line with Skyflash then it is about 5 seconds active time. Of course not with same thrust of 7085 lbf as previous models, however could be said with same total impulse more or less.

Series Mk38 and Mk52 are indeed of two different producers, while first is of Rockedyne second is of Aerojet. But there is much more behind it. Mk38 Mod 0, 1 and 2 are first group and these motors operate in mentioned 3 seconds. On page before this one, there is a table giving nozzle geometry, average time and thrust for Mod.1 These motors are of this concept (Mod.0 in this cross cut view). Cylindrical grain molded, cured and then inserted in chamber. Free burning all around of this pipe formed grain. These elements which can be seen in sectional view are for positioning of the grain in chamber assuring necessary gap between burning surface and inner wall of the chamber. Differences between Mod.0 to Mod.2 should not be some significant, these pressure to time diagrams are for Mod.0 and Mod.1, and here can be seen slight pressure difference (1200 vs 1300 psi) Mk38 Mod.3 and Mod.4 however are of completely different concept, these have grain casted directly in chamber and burning from inside, in channel with star formation. This sectional view is Mk38 Mod.4 with 5-point star channel. Nozzle is with different dimensions compared to previous Mods, burning time surly is not 3 seconds but more about 5 to 6 seconds. And this concept of motor I believe should be in AIM-7E2.

Although this topic is not related to Sparrow, just to ask about this AIM-7E-2 because based on this graph it seems so wrong. AIM-7E2 should be very much related to Skyflash isn't it? If I'm not wrong, both are equipped either with motor type Mk52 or motor Mk38 Mod.4 @Karon what motor is behind this graph? Motors of Sparrow 7E family can be divided in three groups: Mk38 Mod.0, 1 and 2 Mk38 Mod.3 and 4 Mk52 and between some of these groups difference is significant. If there will be interest we could shortly go through these motors, although all looks same from outside, inside they are very different, especially these Mods 0, 1 and 2 compared to others

This AIM-7E should go on serious reconstruction and overhaul. Mk38 Mod 0,1,2 as well as Mod 3 and later should give much more speed than presented

As @GGTharos explained, single and dual thrust concepts (with same total impulse) will result with different ballistics. It is of course individually what is acceptable and accurate enough, for my taste, it is significant difference Imaginary case of AIM-54 flying horizontally at 10km, values of Mach number and travel in meters while total impuls is same (26000N*11s+10000N*14s=426000Ns=17040N*25s)

So, after this of today, I’m again very much back to what was my thoughts at very first beginning. Cross cut model’s blurred photo and this data are so much related, simply that on photo “ignited” is giving such values, more or less. Perhaps Mk47 and Mk60 are not even close in principles except having similar total thrust Quickly made output of already studied fuel block model, now with changed nozzle’s data according to document and with slightly reduced burning law compared to one used few months ago ( 2,2*p^0,25 ). These are sea level and 10km values and as previously with not including nozzle throat erosion. Mates, I think dual thrust mode at least for one of these motors must be considered as reality what ever Internet says, there is more than one sign pushing in that direction

I promissed not to bother anymore but I have to Son of a bi..., this motor or these motors will make me crazy, but really This is sectional view of nozzle and blast tube of AIM-54 and in same document this table I was close with estimation of throat diameter, it is a bit smaller (55mm) and exit is a bit wider (238mm), so area ratio is quite bigger than from my estimation (18,5 vs 14,7). But WTF these average thrust values are now, 1000 lbf to 5000 lbf (4448 N to 22241 N) Based on this, it can't be considered as single thrust motor, isn't it

Indeed it sucks down low, and reading what you have in game with 7% practise of uniformity, seems that you have Mk47 down low in realistic numbers but significantly underrated up there, while Mk60 is opposite, up there seems correct but down low highly overrated. This motor is different and 7% practice surely is not good way to have realistic kinematic. Sample AIM-9D is sample which shows that 7% is more or less acceptable, however only for it and motors of similar internal ballistic

New attempt, that from yesterday about AIM-54 is not realistic simply because fuels with such adiabatic coefficients (k=1,1) are not in practice available, especially if we are talking about CTPB This here is very achievable, these characteristics of fuel are just normal for that time and what ever some will think, there is no much difference between all these grades, either of US and Russian origin, either used in air-to-air missiles or surface-to-air missiles all away to just regular artillery rockets filled with composite. Burning rate is also very common, geometry of nozzle together with chamber pressure is in order. Continuous burning surface of 0,716 sq.m with some geometrical features is achievable indeed. And it would fit very easily to 97000 lbs*s and 4000 lbs but only with additional note that values are for let's say 40000 ft This is rough scaled sectional view, it fits to 170kg and with some simple features continuous burning surface can be achieved. Unfortunately photo of cross cut model in better quality I haven't managed to get, author even didn't find time to answer, or good will. In table you can see what kind of specific impulse such overexpanded nozzle will give at sea level. This 209s should not be surprising, simply the laws are that way. I know you in this game have fixed 7%, but as you can see it depends and can vary a lot. Of course it is not easy to make in other way, it is possible but it would take a huge time of work. Just one more document related to all these for eventual ones with skepticism This is similar diagram like previously given for vacuum conditions and for variety of fuels, this one is for dual based propellants (k=1,2 - 1,3) and for atmospheric pressure. You can see what is happening with overexpanded nozzle with ratio 15 and similar when pressure ratio is 33,3:1 or 50:1. Thrust coefficients drop down so much so Isp and Ct in upper calculations should not be surprising I will not bother you anymore with this, think that I got answers I was looking for and that will be enough for me

@DSplayer Thanks for clarification ! Still I will continue with trying, I believe these numbers should be true, or not too much far from true. Here is one more document, not so much but at least wall thickness gives some direction what could be pressure range in chamber

And then for cruise missile after time lost for climbing it should goes down, it will still loose lot of energy going through the atmosphere plus velocity vector will not be so productive. I will always say punch in nose directly is more efficient, like in problematic pubs, there shouldn’t be too much talks but punch first and then talks if necessary

Probably from same reason mentioned, loose of wider view what sides in that time considered as main threats. While one side found cruise missiles as potentially the highest threat that time, other perhaps thought focus should remain at slow flying bombers at high altitudes. Now we can see that drones making hells and everything in counter-measuring is turned upside down

My fault, I didn’t write nothing to explain all these numbers. First two pages is about booster phase of R-33 just to show that specific impulse surely can in line of 270s and more at sea level. It is here mainly about chamber pressure which in correlation with all other makes specific impulse as it is. So in first 5 seconds 100kg of fuel burn out making total impulse of 264,5 kN. Geometry of fuel block follows everything, all characteristics of fuel and geometrical features are very realistic. Exit pressure at nozzle at sea level almost near to ambient pressure, ideal expansion. Next two pages is what could/should be in AIM-54 motor to result with total impulse as in document stated, in sea level conditions. Pressure in chamber should be around 50bar (ok), burning rate should be around 6mm/s (ok), area ratio should be around 17,5 (ok although at sea level lower ratio would be more beneficial), burning surface should be around 0,668 square meters (achievable ultimately) etc etc. Only what is problematic to accept, fuel composition should be some with ratio of specific heats 1,1. Most of composite fuels graded (dual based with metals as well) are with ratio 1,15-1,2 (for only one composition I have data where ratio is 1,13). This result (aimed total impulse) somehow looking for 1,1. Also one more unique characteristic, if thrust is nearly continuous makes this motor as only one I know that is so much overexpanded at sea level. All others have pressure at nozzle exit somewhere near to 1 bar down there and this one is just like constructor wanted all to predefine for altitudes

It is true that I’m more familiar with motors of Russian origin, I have much more literature about those ones and perhaps after all reading about those concepts I lost ability for wider observation. More or less any motor that I took in deliberation after some time was figured out, somehow, except this one and that’s why it makes me crazy. I don’t agree with you that all these calculations are without points, my practice showed me that it has grounds and, all right, I agree, that what I said about having or not having sense is wrong. Obviously numbers must have sense only I don’t understand those ones because they can’t be molded in general molds present in so many other motors. Of course all these calculations are not with precision of real ones, but still close enough to make some answers. After so many other motors it gives me right to believe that way. Total impulse is undeniable, it is number which can’t be changed, it is only about how to use that number. And the fact is that all, but really all, documents I’ve read give that number for sea level. The problem is that motor of AIM-54 and given total impulse can’t be molded in mentioned molds, neither one. That’s why now I’m taking line and going in other direction, what should be done to make it as stated. This at the end is one of possibilities, now after finish it, it looks achievable, indeed, only what is constant doubt, it is so different compared to all others, of US and Russian origin

Look mate, this is not what I’m doing for living but as mechanical engineer with decades of working experience I know some sh.t about it. Thermodynamic, fluid dynamics and mechanics in general are parts of all this, those are not assumptions but questions risen from calculations. First we need to remove prejudices that US or Russian rocket technology is better than other, I’m giving both equal, in some segments one is slightly better in some others second is slightly better. But like already said, physics is same everywhere. Here it is one more “random” rocket, motor actually Smerch rocket, composite fuel type PD-13/9 which is HTPB based, same and similar subtypes like PD-17/18 or PD-19/15 or PD-14/18 are more or less in all recent Russian air-to-air rocket motors, surface-to-air as well. Not rubbish, but high grade. Just sample to express that something smells with those numbers given to AIM-54. For Smerch I have everything and that’s why it is suitable to use it as one more sample. Total impulse is 82000kg and fuel weight is 329kg so specific impulse is 249s. To repeat numbers of AIM-54, 97000lbs*s and 376lbs of fuel making specific impulse 258s. All right, let’s try now in other way… Two equations, just two. F is thrust, pk is chamber pressure, Skr is nozzle throat area, pa is ambient pressure, S is area ratio (ratio of exit and throat area), Cp and Ct are thrust coefficients, in vacuum and at ambient pressure respectively, thetas are losses. And now inputs for Smerch motor, nozzle throat diameter 101mm, exit diameter 255mm, adiabatic coefficient k=1,18 , average working time 6 seconds, chamber pressure for it 105bar… S=6,374 and Cp for k=1,18 is 1,688 [0,157*ln(S)+1,3972] or manually from -> Ct=1,688-(101300*6,374)/(0,98*0,98*10500000)=1,624 F=0,98*0,98*1,624*0,00801*1050000=131175N Ftot=131175*6=787000N or 80000 kg And now @Temetre you try with AIM-54, I will give you every possible assist with all this boring math just to figure it out from where the hell this f..king 97000 lbs*s came from. PS: in same time you will get answers from where “insane” Isp for R-33 came from

In addition and in the meantime while waiting for something concrete about Phoenix motors rise up. Motor of Neva/Pechora SAM rocket. Of course 380mm diameter, same as Phoenix and variant which timely correspond to Phoenix. Вес топлива второй ступени (fuel weight of second stage) … 151kg Марка топлива ПЭКА-18Д (Fuel type PEKA-18D) Время работы (working time) …15,3-24 seconds Максимальная и минимальная тяга (max and min thrust) … 3100-1600 kg Суммарный импульс (total impulse) … 35600-34000 kgs Visually it looks like this -> Interesting, 230-232s specific impulse for nearly continuous operating at 50bar chamber pressure. This PEKA-18D fuel is, just like Flexadyne, CTPB based composite and it is with specific impulse (in ideal theoretical conditions) of 247s but at pressure ratio 40:1. All right, let’s see what would be for PEKA-18D at 68:1 … Isp=Isp (40:1) + 190,3 + 76*pk - 3,058*pk^2 - 7000*pa + 25484*pa^2 = 247*9,81 + 190,3 + 76*6,8 - 3,058*6,8^2 - 7000*0,1 + 25484*0,1^2 = 2545 Ns/kg = 259s This seems correct, transparent and true because physical laws are same on east and west. For sure something stinks with those numbers given to Phoenix if read literally or we read it completely wrong.

Does anybody have this document in complete form? This motor will make me crazy Total impulse 97000 lb*s or 431477 Ns together with 376 lbs or 170,5kg of fuel (if all this will be taken as fuel weight because some small part should be igniter, ablative isolation etc) makes specific impulse of 258s. It is huge and it doesn't have any sense. From some old patent documents this Flexadyne fuel can be described as composition of 66%AP, 18%PB and 16%Al. These percentages and in this composition give some ideal and theoretical specific impulse of 261s And now somehow Phoenix motor should be close to ideal value if this total of 97000 lb*s is for sea level . Ideal impulse from diagram is for pressure ratio 68, Phoenix if it is with single thrust of 4000 lbs (17793N) have to be with chamber pressure under 68 bar, and for sure with such nozzle, even if chamber pressure is somehow near to 68bar, no way whatsoever that it will expand in optimized way to atmospheric pressure at sea level. Just with that fact specific impulse of 261s will be lower. Then losses from ideal case, and losses are always present in real case. Loss of heat, loss due to friction, loss in nozzle, loss due to condensation phase, loss of unburned fuel etc etc. Just comparation, I believe this Phoenix fuel is same or very similar to what is in AIM-9D and its motor smoky Mk36 Specific impulse 231s ! And that is how it should be because for this Mk36 motor I'm giving some 50bar to chamber pressure, nozzle configuration is such to give near to optimized expanding at sea level. Something is smelling in these numbers given to Phoenix. Either it is not even close to sea level but numbers given for some high altitudes what is not practise in such documenets, either some words like average are missing. Total impulse of 431000 Ns could be possible, but if motor has buster and transition phase when chamber pressure is 1/3 of total time over 100 bar. Motor of R-33 from page before, it is similar in size. It is a bit more heavier, I'm giving it 185kg of fuel and with its way of work (full blood dual thrust) at sea level it gives something like 485000 Ns of total thrust at sea level. That is what my calculation gives and specific in that case is 267s, but at least 5 seconds it is with chamber pressure over 100 bar. Russian composite fuels used in motors of A-to-A missiles are with some 245-250s at ratio 40:1. And it has nice expanding at sea level in these 5 seconds, it expands to ambient pressure. Phoenix motor with single thrust and with such nozzle would be only motor of tactical rockets I was working on, with such awkward design. So if somebody has this document it would be appreciated to see is perhaps something written ''between lines''

As much as I know there is no some official text about what R-33 motor gives except one solid info that active time is 15-24 seconds (it is for +60 to -60 degC), however luckily cross cut view of motor is available and it gives a lot. I think I've already wrote something about this but don't remember where and when It is shematically this form -> Such finocyl grains usually have buster stage then transition part in duration depending of configuration and at last sustaining stage, and more or less after some work thrust f(t) should looks like this at 10 km altitude In game you have very weak booster in 4 seconds then rapid (immediate) drop to continuous sustaining stage taking so long and unnaturally for such configuration. And at the end, velocity M f(t) and distance* nm f(t) *-kinematically overloaded horizontal flight at 35000 ft So, although total travel is similar, distribution in time is significantly different

Diagrams of these Soviet missiles are with lot of issues, inaccuracies and incorrectness, starting from R-33 and backwards

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Can someone help me please. I’m very sure that somewhere on this forum I saw diagram of drag coefficient of AIM-9 missile, and now I can’t find it. I remember it very well, and guess it is related to 9D. I remember it and also remember that reference area was not stated. So if someone can paste it once again and if in addition to determine ref. area, it would be appreciated. I’ve just found some good stuff about what resistance AIM-9B and R-3S shapes produce and I would like to compare it with AIM-9D and R-13M

Thanks mates ! Both those two variants (numbers) are realistic and achievable. I've tried with my model (the second one with slots) to get something close, with two different burning rates And got one with 21 seconds and other with 26 seconds. In both 170 kg of fuel identical properties except burning rates. Values at sea level 343100 Ns (16338 N) and 323448 Ns (12440 N). There is some slight difference in total impulse but at 15km it is more or less equal 420881 Ns vs 419749 Ns Also I've tried external ballistic with these numbers of thrust Both options launched at 15km at 500 m/s (1,695 M), and then after first second of flight I've turned rockets in kinematic overload all their active time, to get altitude pick at 27km and stopped there. As you can see both variants managed it in 60 seconds and slower burning motor resulted with slightly more speed at the end Dashed lines are overloaded flight (angle of attack 4,6 deg and 4 deg respectively) and at the end of counting (27km, 60 seconds) difference in travel is slightly in benefit of faster burning motor. But these differences in speed and travel are really negligible

Few more thoughts about Mk47 and/or Mk60. So AIM-54 is with start weight of 978 lbs (443 kg) and final of 602 lbs (273 kg). Means 170 kg of fuel. Total impulse is they said 97000 lbs (431477 N) and thrust (of some kind, I will take it as average) 4000 lbs (17793 N). Two of several options what crosscut could present -> First will give dual-thrust, second single thrust (or near to continuous thrust) Such total impulse, with nozzle like it is, for me is not possible at sea-level, but only for high altitudes. Of course it is always nice to see big numbers (Americans simply like to do that), but it is also fair to explain such numbers. What DCS gives for these motors as thrust at sea level? Not intention of anything, just to see are we near in thinking.

Self-quoting is not academic but I did it anyway. Single dual-thrust rocket motor ! Source: ''The history of solid rocket propulsion and aerojet - Philip D.Umholtz, Consultant, Porola Valley, CA''