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    "Burevestnik" Nuclear-powered cruise missile

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    Singular_Transform

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Thu Sep 13, 2018 11:02 pm

    GarryB wrote:

    The reactor can be moderated with control rods to ensure it does not over heat, the coolant system delivering heat to the airflow could be ceramic material able to withstand enormous temperatures well beyond what the reactor heats the coolant material to. The heat transfer from the cooling system to the airflow will heat up if the airflow slows down... which will further heat the airflow and increase thrust... accelerating the missile and restoring air flow.

    Means this engine has higher chance to fail than the hydrogen thermal rocket one, and if fail then it will not just simply impact the ground in one piece, but it will disperse the reactor core over a huge area prior of impact.
    So, it is not so easy to test.

    A cruise missile sized nuclear rocket could not contain sufficient hydrogen for an intercontinental flight...

    Remark: all low earth orbit nuclear reactor system had core evacuation/ejection mechanism, to eject the reactor core to a safe parking orbit.
    It is a basic feature : )

    It doesn't fire them up... it accelerates them forward to a higher speed so it climbs to a higher orbit... it is a short term solution to a problem that will need to be solved at some stage.


    So, just summarise : the nuclear ramjet very dangerous, more dangerous than a nuclear rocket engine. If anything happens then it will disperse the core over a big area ( the material doesn't matter, the core in restricted airflow will heat up to positive infinite kelvin , and the control rods have no time to react).

    Space reactor:

    https://en.wikipedia.org/wiki/Kosmos_954
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    GunshipDemocracy

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GunshipDemocracy on Thu Sep 13, 2018 11:15 pm

    rambo54 wrote:there are a whole lot of Russia fans in here.
    Since years they are praising all the fantastic new systems like A-235 (without knowing what is really is), S-500 (every year a new adoration), 40N6 (since at least 4 years it should come around every moment), S-350 and so on.
    To be a real fan sometimes turns down objectivity.

    +
    BTW: maybe it would have been better not to mention the withdrawl of the equipment from Pankovo and not to spoil some dreams

    no worries you didnt spoil me anything thumbsup thumbsup thumbsup Everybody has right to express his opinion here.



    The connection your opinion with realm of reality is yet another question though.

    Everybody can dream, like US about Moon landing as it was real not in studios.
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    GunshipDemocracy

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GunshipDemocracy on Thu Sep 13, 2018 11:18 pm

    Singular_Transform wrote:

    So, just summarise : the nuclear ramjet very dangerous, more dangerous than a nuclear rocket engine. If anything happens then it will disperse the core over a big area ( the material doesn't matter, the core in restricted airflow will heat up to positive infinite kelvin , and the control rods have no time to react).

    Space reactor:

    https://en.wikipedia.org/wiki/Kosmos_954

    nuclear rocket engine is impossible to use on fairly slow and long flying object. The question is what is heating air there. Why not helium/xenon as heat exchanger between engine and reactor?
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    GarryB

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GarryB on Fri Sep 14, 2018 10:10 am


    So, just summarise : the nuclear ramjet very dangerous, more dangerous than a nuclear rocket engine. If anything happens then it will disperse the core over a big area ( the material doesn't matter, the core in restricted airflow will heat up to positive infinite kelvin , and the control rods have no time to react).

    Space reactor:

    Perhaps you might want to give this a read:

    https://howlingpixel.com/i-en/Supersonic_Low_Altitude_Missile

    About project Pluto...

    nuclear rocket engine is impossible to use on fairly slow and long flying object. The question is what is heating air there. Why not helium/xenon as heat exchanger between engine and reactor?

    The whole point of using nuclear propulsion is to extend range to practically unlimited... a rocket motor needs fuel to operate and when that fuel is burned up it means its range is limited by fuel capacity... you might as well use a small cheap jet engine instead of a rocket.

    A nuclear ramjet makes infinitely more sense... the only reason Pluto didn't go ahead was for ethical reasons... so I suspect it will have been restarted and the US will have some in a decade too.
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    Singular_Transform

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Fri Sep 14, 2018 4:22 pm

    The nuclear fuel elements were made of refractory ceramic based on beryllium oxide, with enriched uranium dioxide as fuel and small amount of zirconium dioxide for structural stability. The fuel elements were hollow hexagonal tubes about 4 inches (10 cm) long with 0.3 inches (7.6 mm) distance between the outer parallel planes, with inside diameter of 0.227 inches (5.8 mm). They were manufactured by high-pressure extruding of the green compact, then sintering almost to its theoretical density. The core consisted of 465,000 individual elements stacked to form 27,000 airflow channels; the design with small unattached elements reduced problems related with thermal stresses. The elements were designed for average operation temperature of 2,330 °F (1,277 °C); the autoignition temperature of the reactor base plates was only 150 °C higher. The neutron flux was calculated to be 9×1017 neutrons/(cm2·s) in the aft and 7×1014 neutrons/(cm2·s) in the nose. The gamma radiation level was fairly high due to the lack of shielding; radiation hardening for the guidance electronics had to be designed.

    So, the temperature margin of the Pluto reactor was 150 ceslius.

    Its worked at 1277 Celsius, means only 150 Celsius means complete reactor meltdown.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GunshipDemocracy on Sat Sep 15, 2018 12:36 am

    GarryB wrote:

    A nuclear ramjet makes infinitely more sense... the only reason Pluto didn't go ahead was for ethical reasons... so I suspect it will have been restarted and the US will have some in a decade too.

    unlikely ethical, technical. To defect prone. It is not about doomsday scenario. this is about storage/tests and ability to deliver too. No I dot think anything like that is ever beed applied. In every case Putin said: with nuclear source of energy not engine.

    There's no point repeat same arguments 10times. This is not the way they gone. More probable they have some intermediate medium to pass heat to the engine and moderate reactor.


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    Big_Gazza

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sat Sep 15, 2018 11:22 am

    Singular_Transform wrote:So, just summarise : the nuclear ramjet very dangerous, more dangerous than a nuclear rocket engine. If anything happens then it will disperse the core over a big area ( the material doesn't matter, the core in restricted airflow will heat up to positive infinite kelvin , and the control rods have no time to react).

    No, complete rubbish. A nuclear powered ramjet is perfectly possible for atmospheric flight. Sure, there are engineering issues to solve,but they are not insurmountable, and arm-waving about some long-abandoned USAF project from the 1950s is hardly evidence of anything. Suggesting a nuclear ramjet reactor core can't be built without imminent risk of meltdown due to high operating temperatures is junk "science". Fuel elements and structural components can be build using refractory materials that can withstand several thousand degrees with minimal loss of structural strength. The missile body can be insulated from the reactor heat by encompassing the hot components within a circular duct cooled by a seperate air intake.

    The idea that a thermal nuclear engine can't work using air as a thermal transfer media is just bullshit. FFS, its just a method of injecting heat into airflow and creating thrust via volumetric expansion... air-breathing engines do this everyday on a routine basis tongue Helium or xenon? WTF are you smoking?
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sat Sep 15, 2018 11:37 am

    Singular_Transform wrote:The nuclear fuel elements were made of refractory ceramic based on beryllium oxide, with enriched uranium dioxide as fuel and small amount of zirconium dioxide for structural stability. The fuel elements were hollow hexagonal tubes about 4 inches (10 cm) long with 0.3 inches (7.6 mm) distance between the outer parallel planes, with inside diameter of 0.227 inches (5.8 mm). They were manufactured by high-pressure extruding of the green compact, then sintering almost to its theoretical density. The core consisted of 465,000 individual elements stacked to form 27,000 airflow channels; the design with small unattached elements reduced problems related with thermal stresses. The elements were designed for average operation temperature of 2,330 °F (1,277 °C); the autoignition temperature of the reactor base plates was only 150 °C higher. The neutron flux was calculated to be 9×1017 neutrons/(cm2·s) in the aft and 7×1014 neutrons/(cm2·s) in the nose. The gamma radiation level was fairly high due to the lack of shielding; radiation hardening for the guidance electronics had to be designed.

    So, the temperature margin of the Pluto reactor was 150 ceslius.

    Its worked at 1277 Celsius, means only 150 Celsius means complete reactor meltdown.

    People quoting things they do not properly understand without having the sense to question what they read...

    the autoignition temperature of the reactor base plates was only 150 °C higher.

    What does this mean?  What are "reactor base plates" and why would they auto-ignite at 1,427 deg C? Consider that most stainless steels melt at 1,510 deg C, titanium at 1,670, zirconium at 1854, and tungsten at 3,400.  They certainly don't "ignite".  Any materials subjected to extreme temperatures will be refractories in any case, not metals.

    Interpreting this as meaning that a 150 deg C temperature excursion on high side means a reactor meltdown simply confirms that you have no frigging idea what you are talking about.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Sat Sep 15, 2018 12:07 pm

    Big_Gazza wrote:
    Singular_Transform wrote:The nuclear fuel elements were made of refractory ceramic based on beryllium oxide, with enriched uranium dioxide as fuel and small amount of zirconium dioxide for structural stability. The fuel elements were hollow hexagonal tubes about 4 inches (10 cm) long with 0.3 inches (7.6 mm) distance between the outer parallel planes, with inside diameter of 0.227 inches (5.8 mm). They were manufactured by high-pressure extruding of the green compact, then sintering almost to its theoretical density. The core consisted of 465,000 individual elements stacked to form 27,000 airflow channels; the design with small unattached elements reduced problems related with thermal stresses. The elements were designed for average operation temperature of 2,330 °F (1,277 °C); the autoignition temperature of the reactor base plates was only 150 °C higher. The neutron flux was calculated to be 9×1017 neutrons/(cm2·s) in the aft and 7×1014 neutrons/(cm2·s) in the nose. The gamma radiation level was fairly high due to the lack of shielding; radiation hardening for the guidance electronics had to be designed.

    So, the temperature margin of the Pluto reactor was 150 ceslius.

    Its worked at 1277 Celsius, means only 150 Celsius means complete reactor meltdown.

    People quoting things they do not properly understand without having the sense to question what they read...

    the autoignition temperature of the reactor base plates was only 150 °C higher.

    What does this mean?  What are "reactor base plates" and why would they auto-ignite at 1,427 deg C? Consider that most stainless steels melt at 1,510 deg C, titanium at 1,670, zirconium at 1854, and tungsten at 3,400.  They certainly don't "ignite".  Any materials subjected to extreme temperatures will be refractories in any case, not metals.

    Interpreting this as meaning that a 150 deg C temperature excursion on high side means a reactor meltdown simply confirms that you have no frigging idea what you are talking about.

    https://en.wikipedia.org/wiki/Autoignition_temperature

    It means that the steel burn like wood or coal.
    And that temperature margin calculated for normal air pressure, the engine works with higher pressure, means the auto-ignition temperature is actually closer to the reactor normal operating temperature.

    During iron/steel making there are materials used that float on the top of the steel to separate it from the air ( O2).

    These are solvable problems(using ceramic or whatever), but the very basic characteristic will stay : in the event of restricted flow the reactor will melt like ice in a furnace.
    So, if it ingesting a bird then it will melt down .

    This is the reason why everyone wants to use this as a final doomsday weapon delivery system.

    The US nuclear airplane supposed to use molten salt reactor with heat exchanger.

    However the molten salt is soluble in water....
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GunshipDemocracy on Sat Sep 15, 2018 12:59 pm

    Big_Gazza wrote:air-breathing engines do this everyday on a routine basis tongue Helium or xenon?  WTF are you smoking?  

    it was me not Singular Razz Razz Razz



    Suggesting a nuclear ramjet reactor core can't be built without imminent risk of meltdown due to high operating temperatures is junk "science".  Fuel elements and structural components can be build using refractory materials that can withstand several thousand degrees with minimal loss of structural strength.

    like? what does it mean several thousands and if core is not moderated is there any limit of temp?



    The missile body can be insulated from the reactor heat by encompassing the hot components within a circular duct cooled by a seperate air intake.  

    and if air stops flowing then?
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sat Sep 15, 2018 7:21 pm

    Singular_Transform wrote:What does this mean?  What are "reactor base plates" and why would they auto-ignite at 1,427 deg C? Consider that most stainless steels melt at 1,510 deg C, titanium at 1,670, zirconium at 1854, and tungsten at 3,400.  They certainly don't "ignite".  Any materials subjected to extreme temperatures will be refractories in any case, not metals.

    Interpreting this as meaning that a 150 deg C temperature excursion on high side means a reactor meltdown simply confirms that you have no frigging idea what you are talking about.

    https://en.wikipedia.org/wiki/Autoignition_temperature

    It means that the steel burn like wood or coal.
    And that temperature margin calculated for normal air pressure, the engine works with higher pressure, means the auto-ignition temperature is actually closer to the reactor normal operating temperature.

    During iron/steel making there are materials used that float on the top of the steel to separate it from the air ( O2).

    These are solvable problems(using ceramic or whatever), but the very basic characteristic will stay : in the event of restricted flow the reactor will melt like ice in a furnace.
    So, if it ingesting a bird then it will melt down .

    This is the reason why everyone wants to use this as a final doomsday weapon delivery system.

    The US nuclear airplane supposed to use molten salt reactor with heat exchanger.

    However the molten salt is soluble in water....

    Keep barking up the tree all you like, but again you are misinterpreting what you read....

    Metals don't "ignite" as you suggest, but they will undergo surface oxidisation when subjected to high temperatures in an oxygen-bearing environment. To actually combust in any real sense they need to be in particulate form (eg filings) or very thin sheets/ribbon.  Metallic components in a reactor will not catch fire... that is self evident, and any insistence to the contrary is just BS.


    Last edited by Big_Gazza on Sun Sep 16, 2018 2:36 pm; edited 1 time in total
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Sat Sep 15, 2018 7:33 pm

    Big_Gazza wrote:

    Keep barking up the tree all you like, but again you are misinterpreting what you read....

    Metals don't "ignite" as you suggest, but they will undergo surface oxidisation when subjected to high temperatures in an oxygen-bearing environment. To actually combust in any real sense they need to be in particulate form (eg filings) or very thin sheets/ribbon.  Metallic components in a reactor will not catch fire... that is self evident, and any insistence to the contrary is just BS.  

    https://en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting#Cutting

    In high temperature supersonic airflow the metal parts will burn away in the fraction of second, if the temperature is above the auto-ignition.


    https://www.youtube.com/watch?v=7EGmrPiumEU
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sat Sep 15, 2018 7:41 pm

    like? what does it mean several thousands and if core is not moderated is there any limit of temp?

    Did I say the core wasn't moderated? Power will be controlled by varying the control rod insertion and operating temperature limited accordingly. Sure, you can create hypothetical failure scenarios where rods fail in the fully withdraw condition and cooling air-flow stops - in which case core temperature would skyrocket and the fuel elements will melt. Depending on materials used in the fuel element cladding (likely to be ceramics due to high temperatures) you would likely get loss of containment and molten fuel escaping into the engine. Sounds bad but we are talking about a Doomsday scenario where thermonukes have already given us a real shitty day of eye-ball melting artificial sunlight flash, DNA-shredding hard radiation bursts, and city-wrecking thermobaric detonations.... a handful of smoking rad-filled craters in remote areas or a patch of steaming ocean is fairly low on our list of problems! Laughing

    and if air stops flowing then?

    The air flow won't stop unless the missile stops flying.... and if it should, you simply scram the engine, eg by slamming the control rods fully home with a pyro-technic charge.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sat Sep 15, 2018 7:57 pm

    Singular_Transform wrote:
    Big_Gazza wrote:

    Keep barking up the tree all you like, but again you are misinterpreting what you read....

    Metals don't "ignite" as you suggest, but they will undergo surface oxidisation when subjected to high temperatures in an oxygen-bearing environment. To actually combust in any real sense they need to be in particulate form (eg filings) or very thin sheets/ribbon.  Metallic components in a reactor will not catch fire... that is self evident, and any insistence to the contrary is just BS.  

    https://en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting#Cutting

    In high temperature supersonic airflow the metal parts will burn away in the fraction of second, if the temperature is above the auto-ignition.


    https://www.youtube.com/watch?v=7EGmrPiumEU

    ..and why do you assume that any super-heated metal parts are going to be exposed to supersonic airflow?  Firstly, hottest components will be refractories, not metals.  Secondly, airflow through the "combustion" chamber will be subsonic, because that's how a ramjet works.

    Meh, we could argue this all day and get nowhere.  

    Bottom line is that a nuclear thermal engine using ramjet principle is the only method taht I can see working.  Forget any BS designs using a coolant flow into an exchanger to add heat to the engine airflow or drive a turbine.  Too bulky and heavy to fit into a cruise missile.  Whatever is under the hood of the Burevestnik is not some clunky 1950s tech, but something new, using advances in materials technology, rad-hard control electronics and fast-mechanical control mechanisms. Its classified so we don't know and can only hypothesize, but we can eliminate solutions that don't work...

    For those who doubt the Primitive Ruskies can build something like this, may I remind you that the Exceptionalists in the Clown Empire didn't think that a closed-cycle rocket engine running oxidiser-rich could be practical as the materials science challenges raised by flowing super-hot oxidising gases through the engine would be unsolvable.  They couldn't bring themselves to accept that Kuznetsov had solved the problem back on the late 60s with his NK-15/33s until they bench-tested one of his creations. Score one for the "primitives"...

    Russians excel in metallurgy and materials science.  If anyone can solve the challenges to build a nuke-powered air-breathing ramjet engine, my money is on them...
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Sat Sep 15, 2018 8:50 pm

    Big_Gazza wrote:

    For those who doubt the Primitive Ruskies can build something like this, may I remind you that the Exceptionalists in the Clown Empire didn't think that a closed-cycle rocket engine running oxidiser-rich could be practical as the materials science challenges raised by flowing super-hot oxidising gases through the engine would be unsolvable.  They couldn't bring themselves to accept that Kuznetsov had solved the problem back on the late 60s with his NK-15/33s until they bench-tested one of his creations. Score one for the "primitives"...

    Russians excel in metallurgy and materials science.  If anyone can solve the challenges to build a nuke-powered air-breathing ramjet engine, my money is on them...

    It means two things:
    1. it is too dangerous to use it for everyday work, like power drones or fighter jets.
    2. It is very hard to test during the development phase.

    No 2. actually means that what the US considered as failed test was a purposefully made partial test. Considering that a full, hours long run of it can risk very significant radioactive material emission.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sun Sep 16, 2018 4:36 am

    Yes, it is not suited for "everyday" work, but its a doomsday weapon you launch when you know your goose is already cooked...  No-one is going to care if a few drop out of the sky given that we looking down the barrel of a global Armageddon.

    Yes, testing is difficult.  If I had to develop a test plan I would advocate testing the engine basics in a series of short tests (launching the missile and confirming reactor start and stable operation before a deliberate abort), followed by long duration testing in a wind tunnel. I'd test the guidance system in a specially modified long range bomber such as a Tu-95/142, flying a series of continuous long duration flights for weeks or months on end, landing only to refuel and change flight crews.

    Once the components are individually certified, then its time for full scale tests with Siberian airspace, with the vehicle performing an extended flight over a pre-determined flight path in an enclosed but still vast area.  Keep radio silence but station mobile radars to cover the test area and have the vehicle download its test data at pre-programmed points via encrypted datalinks to ground stations. Finally, provide a remote destruct to force a scram and destruction of airframe but leaving reactor intact, and allow for contingency of manned interceptor to take it down should all else fail.

    Difficult, but certainly not impossible.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Sun Sep 16, 2018 4:49 am

    Singular_Transform wrote:Considering that a full, hours long run of it can risk very significant radioactive material emission.

    I disagree with this, and have stated so on several occasions. While the (mostly unshielded) engine would be expected to generate significant gamma and fast neutron radiation when in operation, it will only be present in the vicinity of the vehicle and will not persist once it has passed. Fuel rods are sealed and no nuclear fuel will leak out, and the exhaust gases will remain unaffected due to brief exposure and lack of heavy particulates able to be transmuted to unstable isotopes.

    The only persistent source of radiation that I could foresee might be small quantities of metallic or ceramic oxides in the exhaust caused by thermal erosion of heat transfer surfaces. The intensity of radiation from such trace materials could be expected to increase proportionally with the mission flight time (as engine structural materials start to accumulate with active isotopes) but its hard to know how much of an issue this could be without knowing the materials specifics. it could range anywhere from insignificant to serious.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GarryB on Sun Sep 16, 2018 1:00 pm

    unlikely ethical, technical. To defect prone. It is not about doomsday scenario. this is about storage/tests and ability to deliver too. No I dot think anything like that is ever beed applied. In every case Putin said: with nuclear source of energy not engine.

    What place does ethics have in a dooms day device?

    In a jet engine the energy source is normally jet fuel... a ramjet engine with a nuclear reactor as a source of heat instead of burning fuel is perfectly feasable... especially for a subsonic missile... there is no need for a temperature of more than 1,300 degrees C.... most modern turbojet engines generate about that temperature already, so making it hotter offers nothing except problems.

    More probable they have some intermediate medium to pass heat to the engine and moderate reactor.

    Why?

    Extra weight for no real benefit...

    The idea that a thermal nuclear engine can't work using air as a thermal transfer media is just bullshit. FFS, its just a method of injecting heat into airflow and creating thrust via volumetric expansion... air-breathing engines do this everyday on a routine basis tongue Helium or xenon? WTF are you smoking?

    Thank you...

    So, the temperature margin of the Pluto reactor was 150 ceslius.

    I gave that example to show a nuclear ramjet is possible, but it does not have to operate at anything like that temperature... the Pluto missile was enormous and carried 24 nuclear warheads... it also flew at low altitude at mach 3... none of which this new missile needs... one or maybe a couple of warheads, and subsonic speeds at low altitude... perhaps transonic speeds at higher altitudes... but nothing like the power of thrust requirements of the Pluto system.

    Solid rocket boosters to get it airborne and a ramjet motor to gradually accelerate it and allow it to climb for a day and then it can fly off in a certain direction... including due south to go for its target.

    It means that the steel burn like wood or coal.
    And that temperature margin calculated for normal air pressure, the engine works with higher pressure, means the auto-ignition temperature is actually closer to the reactor normal operating temperature.

    the operating temperature for a nuclear ramjet engine in a very much larger weapon flying considerably faster is going to be much higher than a nuclear ramjet engine in a much smaller and much slower missile... making the problems much less and the task much easier... they have been working on it the better part of two decades... since 2002 when the US withdrew from the ABM treaty...

    So, if it ingesting a bird then it will melt down .

    Why?

    This is a ramjet... there are no blades or turbines... just heat transfer... design it with birdstrikes in mind and they could simply be sucked right on through...

    like? what does it mean several thousands and if core is not moderated is there any limit of temp?

    The core wont be running all the time from production to use... before the missile is launched the core will be moderated... upon launch the core can be heated up for thrust, but if there is a problem it could just as easily be shut down... or not... a blocked intake means the missile will crash so who cares about a meltdown at that stage... if I designed the missile I would set it up to detonate the warhead if it was going to crash as long as it was not in friendly territory...

    and if air stops flowing then?

    with multiple air intakes the chance of a bird strike blocking all the air flow are pretty much zero... but the obvious solution would be to have it launched vertically with a solid rocket motor and then for the nuclear ramjet to take over and climb to about 10,000m and then fly south and hit the US or Europe from the south pole rather than over the north pole...

    2. It is very hard to test during the development phase.

    Why is it hard to test?

    It is subsonic... you can send fighter jets to fly along side it all the way... replacing them as they run out of fuel... paint the thing bright orange and do it in winter so everything is white and add a bright orange parachute system in the payload section in case there is a problem... in fact you could fly along side in an Il-476 with wireless monitoring of all its systems transmitted in real time the few hundred metres to your chase plane with a manual command to shut down the reactor and deploy the parachute if needed... then send in chem/bio warfare guys to the landing site to deal with any issues if it crashes... fly it away from any populated areas... not a big deal.

    Hell, you could design it so that if there is a problem the whole thing is inflated like a huge hot air balloon that is orange and it descends slowly to the ground... the chase plane with all the instruments can monitor core temperature and other aspects including radiation levels and it can fly circles around the crash site until units arrive to deal with the clean up... but a balloon and parachute system would minimise the debris problem and probably localise everything into one crash site... nice and tidy.
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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Hole on Sun Sep 16, 2018 5:01 pm



    Could explain why Rosatom got an Il-976 plane. Originaly four planes of that type were built for the armed forces to analyse and re-transmit telemetry data from the testing of cruise missiles in remote areas.
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    Singular_Transform

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Sun Sep 16, 2018 6:16 pm



    Just to see, the new technology has high failure rate.

    And in this case the failure means in good case a reactor impact on the ground, bad case a long radioactive trail in the test area.
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    GarryB

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GarryB on Mon Sep 17, 2018 2:12 am

    Those are rocket tests...

    Tests with fuel pumps and hoses through which exotic chemicals that were either very hot or very cold and or highly corrosive or highly flammable were all bundled together in a very enclosed space on a platform subject to very high g forces and acceleration.

    A nuclear ramjet is nothing like that.

    They are not going to make a random design they think might work... material science isn't at the guess work stage.

    Computer models can be used to create something that is very very likely to work first time, but further tests will be needed to refine and improve performance and make sure everything actually works as expected...

    Attaching an entire complete missile in the engine pylon position of an Il-76LL could be used to test the missiles electronics in direct proximity to the working nuclear ramjet for days with inflight refuelling of the aircraft...

    BTW I am surprised you are against such an idea... I would have thought this sort of ground breaking new technology would be something you were actually interested in.

    Typically a ramjet is restricted to subsonic fuel burning, and to go really fast supersonic combustion is needed requiring a scramjet.

    In this case... there is no chemical burning with oxygen... just heat exchange, so in theory there is no issue with supersonic combustion of fuel to heat an airflow so the concept of a scramjet becomes redundant... a jet engines performance is largely determined by the amount of exhaust thrust it can generate and that normally is based on internal temperatures... which generally have to be carefully managed to prevent damage to the engine and its moving parts.

    The very idea that cool air flows could be used to separate the hot air from the internal surface of the engine, while the reactor could superheat the air as it enters the intake, could allow rather enormous thrust levels independent of altitude and flight speed... no flame outs... no running out of fuel even at full thrust settings.

    Obviously this weapon is supposed to be a subsonic low flying cruise missile but could easily become hypersonic medium altitude missile that changes direction and speed every 20 seconds and flys for up to 5 years.
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    Singular_Transform

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Mon Sep 17, 2018 8:29 pm

    GarryB wrote:Those are rocket tests...

    Tests with fuel pumps and hoses through which exotic chemicals that were either very hot or very cold and or highly corrosive or highly flammable were all bundled together in a very enclosed space on a platform subject to very high g forces and acceleration.

    A nuclear ramjet is nothing like that.

    They are not going to make a random design they think might work... material science isn't at the guess work stage.

    Computer models can be used to create something that is very very likely to work first time, but further tests will be needed to refine and improve performance and make sure everything actually works as expected...

    Attaching an entire complete missile in the engine pylon position of an Il-76LL could be used to test the missiles electronics in direct proximity to the working nuclear ramjet for days with inflight refuelling of the aircraft...

    BTW I am surprised you are against such an idea... I would have thought this sort of ground breaking new technology would be something you were actually interested in.

    Typically a ramjet is restricted to subsonic fuel burning, and to go really fast supersonic combustion is needed requiring a scramjet.

    In this case... there is no chemical burning with oxygen... just heat exchange, so in theory there is no issue with supersonic combustion of fuel to heat an airflow so the concept of a scramjet becomes redundant... a jet engines performance is largely determined by the amount of exhaust thrust it can generate and that normally is based on internal temperatures... which generally have to be carefully managed to prevent damage to the engine and its moving parts.

    The very idea that cool air flows could be used to separate the hot air from the internal surface of the engine, while the reactor could superheat the air as it enters the intake, could allow rather enormous thrust levels independent of altitude and flight speed... no flame outs... no running out of fuel even at full thrust settings.

    Obviously this weapon is supposed to be a subsonic low flying cruise missile but could easily become hypersonic medium altitude missile that changes direction and speed every 20 seconds and flys for up to 5 years.

    It is one of the best flying object developed in the past 50 years : )

    Anyway, the problems define the way of development.

    They will conduct a lot of test without reactor, and they test the reactor on test benches .
    When they are confident about the operational ability of the aircraft they will fly it say three times.

    Afterwards they will make a pile of them, and make ready for launch.

    As a bonus it means that the US claim about the "failed" tests true , they haven't tested the missile with core.
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    GarryB

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  GarryB on Tue Sep 18, 2018 2:55 am

    It is one of the best flying object developed in the past 50 years

    Not with those reliability issues...

    Anyway, the problems define the way of development.

    US rocket development has nothing to do with Russian nuclear ramjet development... they are simply not related.

    They will conduct a lot of test without reactor, and they test the reactor on test benches .
    When they are confident about the operational ability of the aircraft they will fly it say three times.

    They started full development in 2002 so they have had over 15 years to develop this technology... and they also have a history of testing new engines on Il-76LL aircraft.

    Why do you think 3 operational tests will be done?



    Afterwards they will make a pile of them, and make ready for launch.

    What makes you think they are not already in service and full production somewhere in the Ural mountains in some secret facility?

    As a bonus it means that the US claim about the "failed" tests true , they haven't tested the missile with core.

    Who gives a fuck about US claims... why do you feel the need to substantiate US claims?

    Perhaps you can also prove that Assad is preparing a batch of Novichok and is going to attack Israel with it to get back the Golan Heights... perhaps a chart showing the development of the Ford escort motor car would suffice for that proof?
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    Big_Gazza

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Big_Gazza on Tue Sep 18, 2018 4:10 am

    GarryB wrote:Perhaps you can also prove that Assad is preparing a batch of Novichok and is going to attack Israel with it to get back the Golan Heights... perhaps a chart showing the development of the Ford escort motor car would suffice for that proof?

    Big chuckles!! Laughing    Spilled my coffee down my crotch but the sizzle was worth it!!... still laughing after 5 minutes...
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    Singular_Transform

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    Re: "Burevestnik" Nuclear-powered cruise missile

    Post  Singular_Transform on Tue Sep 18, 2018 8:08 pm

    GarryB wrote:
    It is one of the best flying object developed in the past 50 years

    Not with those reliability issues...

    Anyway, the problems define the way of development.

    US rocket development has nothing to do with Russian nuclear ramjet development... they are simply not related.

    They will conduct a lot of test without reactor, and they test the reactor on test benches .
    When they are confident about the operational ability of the aircraft they will fly it say three times.

    They started full development in 2002 so they have had over 15 years to develop this technology... and they also have a history of testing new engines on Il-76LL aircraft.

    Why do you think 3 operational tests will be done?



    Afterwards they will make a pile of them, and make ready for launch.

    What makes you think they are not already in service and full production somewhere in the Ural mountains in some secret facility?

    As a bonus it means that the US claim about the "failed" tests true , they haven't tested the missile with core.

    Who gives a fuck about US claims... why do you feel the need to substantiate US claims?

    So, it is hard to test, reason why there is no one in existence.

    Three successful test, without quantitative result ( example temperature profile across core, max/min temperature differences) can give at least 40% chance (with 95% confidence) to see thee serial produced aircraft (if manufactured with the same tolerances/process like the proto) to reach the target.
    With quantitative results it can be increased.

    The question is never that what happens if everything goes well, but how to mitigate the issues.

    The chap who design the experiments/ design/validation process will use the same mathematical / risk analysis model like me.
    So , they assemble the core and frame separately, they run all test on bench/maybe flying aircrafts, and test the airframe without engine as many times as it makes sense.

    And finally, when they are extremely confident they will fly the rig three times.
    Maybe less, but I don't think they will fly it more.

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