Iron Dome Missile Info?

I may want to do a Scale Israeli Iron Dome Rocket, but can't find any good close-up Pics' online of the actual Interceptor Missile. Mostly just Pics' of the Launcher or of the Rocket in flight, and not in High-Resolution.
Does anyone here have any Info they would be kind enough to share with me so that I can atleast do a Sim on it and see if it is worth doing a Scale Model of?

Thanks in advance for any and all Replies.

TR.

Few links:

LINK 1
LINK 2
LINK 3
LINK 4

Canards looking bigger than the fins on this rocket. Wonder what kind of stability issues would be encountered here. Someone should do this up in RockSim and see what comes out.

TopRamen, what scale are you thinking of? At 10' 1:1 is a possibility.

The Tamir interceptor missile is: 3 m long, weighs 90 kg and has a 160 mm diameter.[1] :dark:


[1] - https://www.armyrecognition.com/isr...kets_technical_data_sheet_specifications.html

RocketGeekInFL said:

Canards looking bigger than the fins on this rocket. Wonder what kind of stability issues would be encountered here.

Click to expand...

Yes, the real missile is neutrally stable so it can turn quicker. You can see in some of the news video that it can pass the target then turn around quickly and pursue it.

To make a model stable, you could have the front fins pivot. See:

https://www.rocketreviews.com/descon-python-4-drake-damerau.html

-- Roger

Wow! Thanks for all the Info guys. I'm not anxious to build it, but it would make an interesting subject.
Yeah, stability issues would definitely need to be addressed. I would only be doing it in Mid-Power, so 1:2 Scale at the biggest.
Probably would be a good Idea to do a LPR version first after doing the Sims just to be on the safe side.

jadebox said:

To make a model stable, you could have the front fins pivot. See:

https://www.rocketreviews.com/descon-python-4-drake-damerau.html

-- Roger

Click to expand...

Interesting thread, and very interesting reference and concept...thanks very much, Roger. While that technique requires some extra work really opens up a lot more scale rocket candidates.

Interesting concept indeed. The pivots would have to be very smooth and resilient to torsion and the root edge of the fins far enough from the body tube so that the fins do not end up stuck because of the drag force on them.

As the simulation in the link suggests, you might then end up with an unstable rocket.

I've been scouring the web trying to find info/pictures on the web, but it's scarce. This is an amazing system, if it is actually performing the intercepts. A half- or quarter-scale would be easy to do, but I think I'd go conservative and make the front steering fins removable for flight.

I've actually found more info on the "David's Sling" medium/long range interceptor. The asymmetrical nose cone would be a challenge to build and make fly straight.

jadebox said:

To make a model stable, you could have the front fins pivot. See:

https://www.rocketreviews.com/descon-python-4-drake-damerau.html

Click to expand...

Some real guided missiles do this too. The canards are "floating" so they weathervane into the airflow for improved stability. This is done during the initial launch before guidance is active to help the weapon stay pointed in the right direction. The older Sidewinders before AIM-9X, HARM and Paveway laser-guided bombs all use this technique. More recent weapons tend to have active control immediately at launch to maintain stability.

jadebox said:

Yes, the real missile is neutrally stable so it can turn quicker. You can see in some of the news video that it can pass the target then turn around quickly and pursue it.

To make a model stable, you could have the front fins pivot. See:

https://www.rocketreviews.com/descon-python-4-drake-damerau.html

-- Roger

Click to expand...

Yeah, that's great idea... glad you proposed that Roger... I was going to suggest it myself but you beat me to it.

Great technique... certainly opens the door to a lot of rockets that wouldn't be stable otherwise...

later! OL JR

morlock said:

Interesting concept indeed. The pivots would have to be very smooth and resilient to torsion and the root edge of the fins far enough from the body tube so that the fins do not end up stuck because of the drag force on them.

As the simulation in the link suggests, you might then end up with an unstable rocket.

Click to expand...

So long as the fins can pivot around a common axle (for opposing pairs of fins) it should work. The further forward along the fin root edge the pivot point is, the less destabilizing effect the forward fins have on the stability of the rocket. When one calculates or simulates the stability of the rocket, one must consider the area of the fin IN FRONT OF THE PIVOT POINT as being "glued" to the rocket at the point in front of the axle where they would contact the tube. That amount of area contributes to moving the CP forward. All the fin area BEHIND the pivot point has NO effect on CP, IF the fins can pivot freely back and forth.

The amount of pivoting shouldn't be restricted, but it's not a huge amount of pivoting back and forth. Depending on the conditions, a rocket doesn't usually doesn't experience more than a few degrees of angle of attack... So the fins shouldn't have to pivot but maybe 10 degrees on either side of "neutral" (straight ahead) in a normal flight... of course they should be free to pivot more than that just to make sure...

Later! OL JR

eljefe said:

Some real guided missiles do this too. The canards are "floating" so they weathervane into the airflow for improved stability. This is done during the initial launch before guidance is active to help the weapon stay pointed in the right direction. The older Sidewinders before AIM-9X, HARM and Paveway laser-guided bombs all use this technique. More recent weapons tend to have active control immediately at launch to maintain stability.

Click to expand...

On a Paveway I and II guidance kit, the canards (the fins on the front section) are actuated by a pressurized gas system. The nose (seeker element) is able to pivot slightly to point into the direction of flight. The rear fins are spring-loaded and do not move (once extended)*. The Paveway III has an fixed sensor that is part of the nose assembly. The I and II guidance kits had bang-bang pneumatic servos, that is, they went all the way left/right (or up/down). The III guidance kit has proportional servos that can move a little, or a lot (and enhanced glide/loft capabilities).

*I used to work at the Texas Instruments plant that made the guidance kits. I saw a tail kit "go off" accidentally one day. It jumped about five feet in the air, severely scaring the lady that was packing it.