Announcing Flaming Cliffs 2.0

[GGTharos]

The artificial g-limiter in LOFC.

[IvanK]

I didn't realise there was one any more details ?

[GGTharos]

Ever tried pulling the stick back all the way at say 500kt in a full loaded f-15 (weapons and fuel, no tanks) and see what you get for g? :)

[IvanK]

I didnt think the F15 had a G limiter rather the OWS audio coaching you .

[GGTharos]

I said the LOFC F-15. ;)

[ФрогФут]

If the design is the same and the capabilities are the same then what does it matter whether it uses a microprocessor made in one country or the other.

And who will make it all together? Have you ever worked at production?

My point is that as far as I can tell there is very little, if any, actual difference between the initial R-77 and the post-Soviet RVV-AE except the name and that whatever use of foreign components has more to do with availability/cost of those rather than being an actual "upgrade" to the design.

I think, that the point was loosing the initial production line. It's much more complicated, than you think. Missile production is not Willi Wonka chocolate factory.

[Fudd]

According to the pilot I spoke with, they are a poorer missile to use against a fighter instead of R/T.

 

I started thinking about this in terms of whats already known in lockon. Obviously the values for the parameters are flawed to some extent, but I think we can make sense of this as would be seen by a Mig-29 pilot.

 

We know in lockon that launching an ER or R at a maneuvering target while the missile is in boost phase reduces that chances of a kill. Without being an expert on the physics of this, my guess is that the forward velocity caused by the motor, decreases the effectiveness of the control surfaces and limits the amount of g's the missile can pull. As the missile decelerates its control surfaces become more effective and the missile becomes more maneuverable.

 

So if we apply this to what we know about the Mig-29, with its limited radar range, its possible that a good lock is achieved within the period that an E missile is in its boost phase.

 

Fudd for thought... :music_whistling:

[tflash]

We know in lockon that launching an ER or R at a maneuvering target while the missile is in boost phase reduces that chances of a kill. Without being an expert on the physics of this, my guess is that the forward velocity caused by the motor, decreases the effectiveness of the control surfaces and limits the amount of g's the missile can pull. As the missile decelerates its control surfaces become more effective and the missile becomes more maneuverable.

 

 

Exactly what I was trying to say! ;-)

[GGTharos]

... so you're saying we should destroy its close combat capability instead? ;)

[ФрогФут]

We know in lockon that launching an ER or R at a maneuvering target while the missile is in boost phase reduces that chances of a kill. Without being an expert on the physics of this, my guess is that the forward velocity caused by the motor, decreases the effectiveness of the control surfaces and limits the amount of g's the missile can pull. As the missile decelerates its control surfaces become more effective and the missile becomes more maneuverable.

Everything is fine, except:

1) Missiles' aerodynamics is optimised for high supersonic speeds.

2) When the engine is working, and you have some angle of attact, the thrust helps turning. That was simple school physics.:)

[GGTharos]

Actually I've heard what Fudd is saying from a much more qualified source as well, although about a different missile, and for fairly short range for the initial boost under certain geometries.

 

But yeah, the response was this vague.

 

Everything is fine, except:

1) Missiles' aerodynamics is optimised for high supersonic speeds.

2) When the engine is working, and you have some angle of attact, the thrust helps turning. That was simple school physics.:)

[Fudd]

Actually I've heard what Fudd is saying from a much more qualified source

 

:P

 

:smartass:

[ФрогФут]

and for fairly short range for the initial boost

Obvious. Missile hasn't accelerated enough for maneuver. I think, that's nothing to do with the engine working.:)

[Fudd]

Obvious. Missile hasn't accelerated enough for maneuver. I think, that's nothing to do with the engine working.:)

 

So based on what your saying, and we believe this Mig-29 pilot, then the E version is less manuverable than the regular version?

 

...is this conversation actually having an impact on whats to be decided in Hot Rocks 2.0?

[ФрогФут]

...is this conversation actually having an impact on whats to be decided in Hot Rocks 2.0?

No.

So based on what your saying, and we believe this Mig-29 pilot, then the E version is less manuverable than the regular version?

My vision of how the E missile will be used against fighter differ from GG's, that may be the point of arquing.

Not talking about the amounts of energy, missile will loose on the maneuvering.

Edited February 9, 2010 by ФрогФут

[tflash]

Everything is fine, except:

1) Missiles' aerodynamics is optimised for high supersonic speeds.

2) When the engine is working, and you have some angle of attact, the thrust helps turning. That was simple school physics.:)

 

The large forward mounted fins are there to maximize this effect I guess. It would be interesting to know at which point in flight precisely the missile is most manoevrable. A little bit comparable to a "corner speed"?

[GGTharos]

Actually the phrase 'fly past the target because its boosting so hard' was used. ;)

 

Obvious. Missile hasn't accelerated enough for maneuver. I think, that's nothing to do with the engine working.:)

[Fudd]

Actually the phrase 'fly past the target because its boosting so hard' was used. ;)

 

We dont have a single rocket scientist in this group of computer nerds??

 

I met a one or two at Berkeley... one thing is for sure, they weren't out partying with women on a Saturday night!

 

:D

[ФрогФут]

Actually the phrase 'fly past the target because its boosting so hard' was used.

Ohohohoh... Well, i'm not a pilot. I'm an engineer. My part of the missile is seeker. But my physics knowledge tells me the opposite opinion. Unless we have some papers on this...

The large forward mounted fins are there to maximize this effect I guess.

For supersonic missiles, less wings make it more maneuverable. Look at mica, amraam etc.

[GGTharos]

Consider the tremendous acceleration of the missile during the boost phase - while initial speed is 'ineffective' the actual speed of the missile is increasing very fast, so the PN correction that was just issued is suddenly not valid by a very large margin, and the degrees/sec of turn shrinks rapidly as well. Just a guess on my part.

 

Ohohohoh... Well, i'm not a pilot. I'm an engineer. My part of the missile is seeker. But my physics knowledge tells me the opposite opinion. Unless we have some papers on this...

[Case]

Actually the phrase 'fly past the target because its boosting so hard' was used. ;)

Interesting notion. There might be some truth here, but I'm also curious about the consequences of the missile just having been launched. It will be very much faster compared to its target, which may mean that proportional navigation will put the target directly on the velocity vector of the missile and that it may not need to manoeuvre much at all.

 

Anyway, it would be interesting to do some simple simulations here, but I guess simulating the missile drag will be the tricky factor.

Edited February 9, 2010 by Case

[GGTharos]

No, the drag isn't the factor. It's seeker (mechanical and electronics) - processor - INU - autopilot-mechanical component interaction. It is pretty complex and not a piece of cake to simulate, if you REALLY want to get things right ... there are things that happen in these interactions that really need to be accounted for if science and verification/modeling are your goal.

[Case]

No, the drag isn't the factor. It's seeker (mechanical and electronics) - processor - INU - autopilot-mechanical component interaction. It is pretty complex and not a piece of cake to simulate, if you REALLY want to get things right ... there are things that happen in these interactions that really need to be accounted for if science and verification/modeling are your goal.

Probably, but for the sake of a simple simulation things can be assumed here. In retrospect, the same is true for drag, even more so in the boost phase.

[GGTharos]

I can answer with 'maybe', but I believe that seeker settling plays a big factor in this.

[Alfa]

And who will make it all together? Have you ever worked at production?

 

Yes as a matter of fact I have :)

 

I think, that the point was loosing the initial production line.

 

No that was your point - mine was whether the shift from one production facility in Ukraine to another in Russia lead to a change to the actual design and whether the name change from "R-77" to "RVV-AE" covers any significant difference in missile charteristics and performance.

 

It's much more complicated, than you think. Missile production is not Willi Wonka chocolate factory.

 

LOL....such arrogance. I tell you what I think - I think that even the Willi Wonka chocolate factory has an R&D department and that the general composition, shape and taste of its chocolates is determined prior to full scale production :D .