Questions and Ideas

victor1985 wrote:

medo wrote:

victor1985 wrote:

GarryB wrote:It isn't necessary to put the radar in the nose, but most radars are large... too round to fit in the wings and you have to have a nose on the aircraft whether it has a radar in there or not so it just makes sense to fit the radar there.

yea and i thinked to antennas not radar itself. let me put a question:a radar power (distance in wich he is effective) depends on electricity? mean depends on power of the curent?
few monts ago i tried to make on paper a design of a flux generator. the ideea was that meta materials cooled whit freon spins around metal tracks and generate energy
also for a aircraft the air could be used to generate energy

Of course a radar power depend on electricity, which were produced from engines or from additional APUs. Su-30SM have quite powerful radar Irbis-R with 15 kW peak power, the same as V-004 radar in Su-34 and Zaslon in MiG-31. Su-35 have more powerful engines and its Irbis radar have 20 kW peak power. I think PAK-FA will have similar peak power of its radar. Su-34 also have powerful ECM electronics and it have additional APU in tail sting. Powerful radars are also more resistant to jamming as many times jamming signal doesn't have enough power to jam radar signal, what mean jammer have to come closer or have to be stronger.

Smaller single engine fighters have less powerful radars, usually with 5 kW peak power.

APU meaning what? some kind of extra sistems that gain energy from wind or omething? since some aircrafts are designated not to be stealth and dont need special materials on it you and they defend themselfs whit the weapons on board why just not fill the aicraft body whit solar panels? or at last some parts  

APU meaning auxiliary power unit. It is additional electro generator. Tanks and SAMs also have them to operate their systems without using their main engine.

so that means all depends on how efficient are those APU. how a radar works more exacly? and what avionics means?

APU meaning what? some kind of extra sistems that gain energy from wind or omething? since some aircrafts are designated not to be stealth and dont need special materials on it you and they defend themselfs whit the weapons on board why just not fill the aicraft body whit solar panels? or at last some parts

Aircraft already have engines to keep them airborne... but some allow more take off power than others.

the ones that lack a lot of take off power for powering electronics on board the aircraft can be fitted with small engines called APUs that can power the electronics while on the ground with the engines turned off or in flight when more power is needed.

APUs generate rather more power than solar panels.

so that means all depends on how efficient are those APU. how a radar works more exacly? and what avionics means?

When designing an aircraft it will be known what sort of systems it will be carrying and what sort of power requirements it will have. Generally there is enough energy potential from the main engines to power everything.

Avionics is an abbreviation for Aviation electronics.

i thinked that special drones can be made for test missiles on them....
similar can be done whit ground forces or naval or whatever
even low or totally invisible on radar drones can be made whit various speeds and volumes

the main problem with unmanned drones is they tend to be fairly stupid.

If you put lots of sensors on them and self defence systems and try to make them stealthy... all of a sudden you have to duplicate critical systems too and they get bigger and heavier and rather more expensive, yet still don't have a pilot on board that can bring them home if something fails.

If you want to fill your own skies with armed drones that can make their own decisions you might lose a few civilian airliners. It would be the same problem if you operate all your unmanned drones in enemy airspace.

And of course when your own ground based air defences now have streams of armed drones flying all around the place as well as manned aircraft coming and going mistakes become inevitable.

Mistakes are always possible but having a man in the seat able to make decisions greatly increases the performance of the system.

is said that the rockets cant have great speeds. but i think is easy. you just get a ICBM whit a fuel tank enough for 10 000 km and consume it in just 1000 km. that would give huge speed to rockets. it doesnt matter that would not be long distance weapon but that the nation borders would be secured. just add more pipelines from fuel tank and would have a great speed. this apply to simple missiles too.

is said that the rockets cant have great speeds. but i think is easy. you just get a ICBM whit a fuel tank enough for 10 000 km and consume it in just 1000 km. that would give huge speed to rockets. it doesnt matter that would not be long distance weapon but that the nation borders would be secured. just add more pipelines from fuel tank and would have a great speed. this apply to simple missiles too.

These ICBMs have enormous speed... in fact 10,000km range missiles is close to the limit of speed before you start leaving the earths orbit and head out into space.

A ballistic missile is a bit like a rifle bullet fired from a gun... a bullet is accelerated down the rifles barrel and then when it leaves the barrel it coasts to the target under its own momentum.

With a ballistic rocket the first engine burns fairly rapidly and then falls away to reduce weight and then the second engine burns for a few minutes and then it too falls away and then the last engine burns for a minute or two and then the payload coasts to its target and falls onto the target. The engines are used to climb and accelerate the missile to high speed and high altitude and then the warhead coasts to the target area and falls onto the target.

A 10,000km rocket does not operate its rocket engines all the way to the target.

Even battlefield rockets like Grad, Uragan, and Smerch don't burn their rocket engines all the way to the target.

Something like an ATGM which flys low and slow and has no wings to hold it in the air will use rocket power all the way to the target.... just like a cruise missile, which does have wings, but generally has a jet engine.

GarryB wrote:

is said that the rockets cant have great speeds. but i think is easy. you just get a ICBM whit a fuel tank enough for 10 000 km and consume it in just 1000 km. that would give huge speed to rockets. it doesnt matter that would not be long distance weapon but that the nation borders would be secured. just add more pipelines from fuel tank and would have a great speed. this apply to simple missiles too.

These ICBMs have enormous speed... in fact 10,000km range missiles is close to the limit of speed before you start leaving the earths orbit and head out into space.

A ballistic missile is a bit like a rifle bullet fired from a gun... a bullet is accelerated down the rifles barrel and then when it leaves the barrel it coasts to the target under its own momentum.

With a ballistic rocket the first engine burns fairly rapidly and then falls away to reduce weight and then the second engine burns for a few minutes and then it too falls away and then the last engine burns for a minute or two and then the payload coasts to its target and falls onto the target. The engines are used to climb and accelerate the missile to high speed and high altitude and then the warhead coasts to the target area and falls onto the target.

A 10,000km rocket does not operate its rocket engines all the way to the target.

Even battlefield rockets like Grad, Uragan, and Smerch don't burn their rocket engines all the way to the target.

Something like an ATGM which flys low and slow and has no wings to hold it in the air will use rocket power all the way to the target.... just like a cruise missile, which does have wings, but generally has a jet engine.

another thing that i dont understand is why with each stage a engine is dropped? the stages could be dropped from front to back leaving a single engine drive the rest of the rocket. in this the rocket wouldnt need to start a engine every time a stage drop. every engine that start means more possible problems so a drop from front with the engine in the back of the rocket tail would mean a single engine and no other possible problems. only problem would be closing the pipes which are separated from the drop stages.

GarryB wrote: The engines are used to climb and accelerate the missile to high speed and high altitude and then the warhead coasts to the target area and falls onto the target.

I think Russia can adopt a scoring mechanism to ascertain missile performance during tests similar to that of the US. USAF has a very simple but effective scoring mechanism to see how missile tests perform at the basic level (apart from detailed telemetry etc). they assign a score to each phase.

For example booster ignition and into the air - 1 point.
transition to flight - 1 point.
navigation- 2 points etc.

This scoring mechanism allows for iterative improvements as/when necessary.

point is that at a given number of products (here rockets) an error apears. point is that you cant verify all because once lauched cannot be stopped. one idea would be to fuel them whit few fuel just for 100 km and test them in flight. they could be lauched in sea and after fall to be recuperated from the sea. another ideea in use today is to test every stage separate on the ground. stages beeing kept on ground by something. something could in theory keep rocket down whit all stages mounted but that would mean a huge device. their thrust is huge and would fly whit anything attached or worst damage themself during test. mobile attached things could simulate fly for rockets. or underground water tests. also small scale rockets like ICBMs design verify part of problems.

an attached parachoute could avoid damage after fall is sea.

also computer simulated flight of rocket helps. whitout make any mistake whit the rocket itself. point is a lot of parameters and the computer programs are complex and even them can give errors. sure separate test for each component can be made on computer or 2-3 components linked toghether but that doesnt look exacly like a totally simulation of flight. in few years computers would become more intelligent than people and they could offer solutions for tehnical problems of the rockets. even today computers can simulate a better arrangement of equipment in rockets and planes. or give solutions to a mechanic problem. using computers for just parts of the engine would give answers before computers getting more intelligent

Running a civilian operation and a military one are not quite the same thing.

AFAIK the nuclear power stations in Russian territory are state run... so could be both civilian and military... with the military handling all the nuclear materials for safety reasons.

The same state agency that runs Russian reactors also builds and services reactors on foreign soil so it makes sense for them to use reactors in Russia to reenrich spent fuel rods from foreign reactors into fuel rods that can be sold back to the foreign customers.

another thing that i dont understand is why with each stage a engine is dropped? the stages could be dropped from front to back leaving a single engine drive the rest of the rocket. in this the rocket wouldnt need to start a engine every time a stage drop. every engine that start means more possible problems so a drop from front with the engine in the back of the rocket tail would mean a single engine and no other possible problems. only problem would be closing the pipes which are separated from the drop stages.

Think of it in terms of a transport plane carrying a small aircraft with a motor bike on board... to fly 10,000km from New Zealand to the US you need a large aircraft, but once you get to the continent of the United States a smaller plane can be used to fly 1,00km across country to get within 100km of your destination where you land and ride the motorbike direct to the door of the house you were trying to get to.

What you are suggesting is to connect the fuel tanks of the small aircraft and the motor bike to the main engines of the large transport aircraft and fly direct to the house.

As you start to drop weight you don't need the big powerful main engine any more... their high thrust is not needed when the vehicle is already moving and is not so heavy so smaller less powerful but also more fuel efficient engines make more sense for each stage.

I think Russia can adopt a scoring mechanism to ascertain missile performance during tests similar to that of the US. USAF has a very simple but effective scoring mechanism to see how missile tests perform at the basic level (apart from detailed telemetry etc). they assign a score to each phase.

For example booster ignition and into the air - 1 point.
transition to flight - 1 point.
navigation- 2 points etc.

This scoring mechanism allows for iterative improvements as/when necessary.

I rather suspect they already have their own system of evaluating performance and for identifying areas that need improvement.

It probably isn't simple, but then there are a lot of parameters to monitor and evaluate.

point is that at a given number of products (here rockets) an error apears. point is that you cant verify all because once lauched cannot be stopped. one idea would be to fuel them whit few fuel just for 100 km and test them in flight.

They already perform ground testing of rocket engines, including long tests using rather more fuel that could be carried by the rocket to test the performance.

At the end of the day you have to test the whole vehicle including stage separation and impact accuracy and that is what the missile range is for.

Werewolf wrote:

Some Youtube top 10 video scoring system?

They have a evaluation system that is integrated and transfers data which is monitored by VKO space center. It monitors operation of missile during launch and flight and gives data of fuel consumption, g-load levels, temperatures, phases of launch, trajectory etc pp, but nice to know US relies on YT top 10 video scoring methods....high-tech.

You could not capture the essence of what I said. I said during a missile test, it is not necessary that the entire test ends in a failure. Certain aspects of the test may fail. That is where a scoring system comes into play.

GarryB wrote:I rather suspect they already have their own system of evaluating performance and for identifying areas that need improvement.

It probably isn't simple, but then there are a lot of parameters to monitor and evaluate.

x2. But there are no such Russian performance evaluation of individual stages, aspects etc of a missile test that is available, at least in public domain.

Take the Bulava test failure for example. It malfunctioned two minutes into its flight.Following the test failure, Russia's defense chief ordered an additional five trial-launches of the weapon.

This IMO would not be necessary if the individual aspects, parameters of the Bulava was tracked and subsequently scored. This relates to manufacturing errors as well.

The USAF scoring system for ICBM tests of late is working like a charm.

GarryB wrote:

another thing that i dont understand is why with each stage a engine is dropped? the stages could be dropped from front to back leaving a single engine drive the rest of the rocket. in this the rocket wouldnt need to start a engine every time a stage drop. every engine that start means more possible problems so a drop from front with the engine in the back of the rocket tail would mean a single engine and no other possible problems. only problem would be closing the pipes which are separated from the drop stages.

Think of it in terms of a transport plane carrying a small aircraft with a motor bike on board... to fly 10,000km from New Zealand to the US you need a large aircraft, but once you get to the continent of the United States a smaller plane can be used to fly 1,00km across country to get within 100km of your destination where you land and ride the motorbike direct to the door of the house you were trying to get to.

What you are suggesting is to connect the fuel tanks of the small aircraft and the motor bike to the main engines of the large transport aircraft and fly direct to the house.

As you start to drop weight you don't need the big powerful main engine any more... their high thrust is not needed when the vehicle is already moving and is not so heavy so smaller less powerful but also more fuel efficient engines make more sense for each stage.

point is that at a given number of products (here rockets) an error apears. point is that you cant verify all because once lauched cannot be stopped. one idea would be to fuel them whit few fuel just for 100 km and test them in flight.

They already perform ground testing of rocket engines, including long tests using rather more fuel that could be carried by the rocket to test the performance.

At the end of the day you have to test the whole vehicle including stage separation and impact accuracy and that is what the missile range is for.

but i have a question: rocket engine is not like car engine....is just a mix of oxidant and fuel....in this controlling amount of fuel you have n engines in one single....as far i understand.....so the big engine from tail could be made a smaller one by controling the fuel and oxidant during flight. so is not need in my opinion for separate engine for every stage.

a ground tested missile is totally similar whit a air test? all components can be tested on ground?

You could not capture the essence of what I said. I said during a missile test, it is not necessary that the entire test ends in a failure. Certain aspects of the test may fail. That is where a scoring system comes into play.

Testing rockets is not some sort of sport, where you try to earn bonus points so if you come up against a rival in the semi finals you want more points than them so that if it is a draw you beat them on points.

Missile tests are varied... if they are testing for flight range then they probably wont fit a real warhead... just ballast. If the ballast does not accurately hit the target then it is not really a count against the system and wont make the test a failure as ballast wont perform the same as a real warhead.

US talk of partial failures makes me cringe... this isn't a maths test for a 6 year old... ironically.

Testing is not a pass = succeed, fail = fail thing. If people stopped working on things because they had a few setbacks we would still be living in caves.

But there are no such Russian performance evaluation of individual stages, aspects etc of a missile test that is available, at least in public domain.

These are not new CDs being released... there is never going to be a running progress report on this stuff... this stuff is a secret... and there is no reason for them to do anything else.

There wont be a discovery channel documentary on the development and production of Russian military or civilian rockets.

Take the Bulava test failure for example. It malfunctioned two minutes into its flight.Following the test failure, Russia's defense chief ordered an additional five trial-launches of the weapon.

they aren't just going to launch the same weapon in the same condition five more times... they are just given five more opportunities to work out what the problem was and solve it. they will be carefully examining the telemetry from the rocket and all the data collected by all the sensors and systems tracking the rocket to work out what happened, and they will likely be looking at previous failures to look for patterns in the telemetry.

This IMO would not be necessary if the individual aspects, parameters of the Bulava was tracked and subsequently scored. This relates to manufacturing errors as well.

Sorry... what? You think they just launch them and hope everything goes well? Those rockets are full of electronic monitoring devices that send back all sorts of information during a test... and not only that they have dozens if not hundreds of radar and optical systems let alone space based sensors tracking the missile.

The USAF scoring system for ICBM tests of late is working like a charm.

Could that be because all their ICBM tests are of rockets that have been in service for decades and are not actually new systems?

but i have a question: rocket engine is not like car engine....is just a mix of oxidant and fuel....in this controlling amount of fuel you have n engines in one single....as far i understand.....so the big engine from tail could be made a smaller one by controling the fuel and oxidant during flight. so is not need in my opinion for separate engine for every stage.

I have heard of big 6 cylinder car engines that can operate only 4 cylinders when they are not towing caravans or doing hard work like climbing steep hills. It is still an enormous big heavy engine even when it is using less fuel.

Think of a rocket as being like a helicopter... to get airborne and stay airborne thrust has to exceed weight so keeping a heavier engine but just reducing its thrust is not a good compromise.

Remember part of the reason for dropping stages is to reduce weight.

a ground tested missile is totally similar whit a air test? all components can be tested on ground?

Just the engines... not stage separation... that is done in test flights.

yes but the "engine" is just a nozzle which guide the thrust. having a single engine reduce the problems. how much after all a nozzle engine can weight? its weight is not important. or you reffer to the mix space tank of the oxidant and the fuel? that cant either weight too much...... advantages of less problems whit single engine are more that those of reduced weight.

Just the engines... not stage separation... that is done in test flights.

ok ...... whit the advantage that is flight test both engine and stage separation can be teste.
also i think that first stage could be short just like last one. cause today a lot of space whit a lot of countermeasures must be travelled. so dropping fast a stage reduce weight. this indicate a more stage rocket because at the same lenght 2 rockets one whit 2 stages and another whit 4 stages that whit 4 stages has advantage of reduce weight during flight. a 2 stage must carry more weight. unless a more bigger engine is for first stage. but that would means consume fast fuel. ofcourse add speed but sure the tehnicians knows which reach deeped distance: a bigger engine but fast consume or a small engine but more stages and reduced weight

Hello all, I just recently got into 3D modelling, And I have started modelling the T-72 ural and am planning to simulate its armor for personal purposes plus if I do somehow make some reliable testing simulation I can share results here maybe one day I can make
a good simulator can anybody give me measures of T-72 ural's hull height and turret height and length? I may have more questions and I am a "noob" at modelling but I am hoping I will be able to get good at over time. I will be asking other questions if I do somehow get past this part, And I would be very grateful if there is a even novice modeler on here that can give me some help and advice.

I seem to remember there were quite a few very capable modellers on this forum... check the introductions area for them....

GarryB wrote:I seem to remember there were quite a few very capable modellers on this forum... check the introductions area for them....

Ok I'll check on them.

So basically what is about electronic warfare? Asvlong i know electric current is about moving of electrons. Because every atom can be negative or positive (depending which is higher in number electrons or protons). I also found recently that negative or pozitive atoms are called IONs and deficite of neutrons are called ISOTOPHE. I try to understand right now how a battery works and how a EMP works( as far i understand is about sending a huge amount of electrons in the electric circuit).

victor1985 wrote:So basically  what is about electronic warfare? Asvlong i know electric current is about moving of electrons.

An electrical current is really just a mass-movement of electrons, a big sea of them. The greater the amount of them passing some point in the circuit per secound, the greater the current (current is measured in amperes; 1 ampere = 6.241×10^18 electrons passing through per second).

A total electrical charge equivalent to that of 6.241x10^18 electrons (or protons), is called a coulomb.

Therefore you can say that an ampere - is equal to 1 coulomb of charge passing through per second.

Because every atom can be negative or positive (depending which is higher in number electrons or protons).
I also found recently that negative or pozitive atoms are called IONs

An atom with an electrical charge, is not called an atom, it is indeed called an ion as you have said.

deficite of neutrons are called ISOTOPHE.

Isotope, not Isotophe.

Indeed, but this has nothing to do with electricity. More nuclear physics, radioactivity and so on.

I try to understand right now how a battery works and how a EMP works( as far i understand is about sending a huge amount of electrons in the electric circuit).

There are configurations in which lattices of atoms, arranged as a big structure, are able to have free outer electrons, that are free to hop from one atom to the next, so long as all the other electrons of all the other atoms are also attracted to go the same way and at the same time.

Such a material is called a conductor. All metals are arranged this way. So is graphite (a form of carbon).

This behaviour generates a current; that sea of electrons starts moving - and this is what electricity is.

What causes this behaviour - is an electromotive force (from a moving magnetic field, or towards the positive terminal of a battery lets say). Such a force can described in terms of voltage. The greater the voltage - the more powerful it is; the more the electrons will be compelled to move.

A battery basically works via some mechanism that gives one of its terminals a positive charge relative to the other one. Because the two terminals have different levels of charge, a voltage manifests itself, that starts moving current across some conductor (wire) connected to the terminals.
Typically this mechanism is a chemical reaction - which causes the accumulation of electrons at one of the terminals - leading the other terminal to be positive relative to the one where the electrons are partying at.

An EMP pulse, like that coming from a nuclear explosion - is basically just a very short, but very strong magnetic field that moves at the speed of light. When it reaches any conductor; it gives the free electrons of that conductor a HUGE spike of energy/momentum.
Now, this doesn't really cause much of a current - because the EMP burst is traversing at approx 3,000,000,000 metres/second while a typical conductor or wire might not be longer than a few metres long along the axis of movement of the EMP burst. If you happen to be touching some metal bar or whatever when the pulse passes over, you won't be harmed - the voltage is very high but the current (electrons per sec, remember) is very minor owing to the extreme shortness of the phenomenon.
Current is what kills you really, not so much voltage.

However, for any sort of working electronic compoments, with a current already moving; that EMP burst will cause a huge spike in that current, however short, and this will easily be enough to burn out all the sensitive microelectronic components, switches, etc... that are rated for much lower charges and will simply melt if you expose them to a many-times higher charge even for a nanosecond.

I wanna ask something: a ampere is a 6,241x 10^18 electrons that are moving throught circuit. Question is: those electrons where are they after moving? And a coulomb is stationary electrons..... where they stay in a battery and in a electric circuit togheter and separate?