Fuel tank exploding after (radial) decoupling

[Gaarst]

So I was testing this new rocket I made, and when decoupling the radial LF boosters I used in the first stage, the fuel tank they were fixed on suddenly explodes from overheating (no collision causes the thing).

(Layout is: 4x Jumbo64 strapped to a Kerbodyne 14400 with Manifold radial decouplers)

Using debug thermal colors: there is no overheating before decoupling (the tank is show red) but right after, the tank suddenly goes yellow and explodes.

Am I doing something wrong or is it a new thing from 1.0 physics or a bug ?

(I can provide screenshots if anyone asks.)

Edited April 30, 2015 by Gaarst

[basic.syntax]

What engines are below these tanks? Are any parts beside strut connectors, attached to them? A screenshot would be helpful for someone trying to reproduce the setup.

[Gaarst]

As you asked, here are a few screenshots:

In the VAB, close up of the junction that causes the problem:

Screenshot just before decoupling the boosters:

And right after decoupling:

And then boom...

If you want to try and see by yourself, here the .craft file of the rocket:

https://www.dropbox.com/s/l105i6vymqs2js2/Heavy%20Launcher%201_0.craft?dl=0

[Randazzo]

The separatrons are cooking the fuel tank. Place them more toward the outer facing of the booster tanks and angle them to produce the desired thrust vector. If you have them pointing at the interior tank, the heat just blows it up.

[Gaarst]

The separatrons are cooking the fuel tank. Place them more toward the outer facing of the booster tanks and angle them to produce the desired thrust vector. If you have them pointing at the interior tank, the heat just blows it up.

It is not the separatrons, I had the problem before adding them. I thought there was a collision and this is why I added them at first, but they are definitely not the cause of the overheating.

[Randazzo]

It is not the separatrons, I had the problem before adding them. I thought there was a collision and this is why I added them at first, but they are definitely not the cause of the overheating.

Before this, your massive boosters were colliding with the tank. Now, your separatron placement is overheating the tank. I can see it happening on your thermal overlay, and I know that's what is happening from experience.

Here's a high-tech diagram from a professional artist:

You'll need a similar arrangement to avoid cooking your tank. You may need to double up on them since the thrust is reduced due to the outward angles. I'm not going to argue you into trying this, but what do you have to lose? If I'm wrong, you get to gloat.

Edited April 30, 2015 by Randazzo

[KatzOhki]

Wait for your craft to be destroyed and then the window that pops up should give details on whether its overheating vs. a collision.

[amorymeltzer]

Wait for your craft to be destroyed and then the window that pops up should give details on whether its overheating vs. a collision.

Or just press F3

[Gaarst]

Before this, your massive boosters were colliding with the tank. Now, your separatron placement is overheating the tank. I can see it happening on your thermal overlay, and I know that's what is happening from experience.

Here's a high-tech diagram from a professional artist:

http://i.imgur.com/vZgMpCW.png

You'll need a similar arrangement to avoid cooking your tank. You may need to double up on them since the thrust is reduced due to the outward angles. I'm not going to argue you into trying this, but what do you have to lose? If I'm wrong, you get to gloat.

Yep, you were totally right

Thank you very much

But I could never imagine those little TNT sticks could generate so much heat...

[Randazzo]

Glad to help

[basic.syntax]

in this case, picture = 103.14159 words

[mrclucks]

Excellent professional diagram for seperatron placement.

I'm still surprised that people use seperatrons though. I haven't had to use any since I was a wee kexplorer still trying to get to the mun.

I find that if you place your decoplers in the center of mass of the empty tanks/engine stack, then they just slide past you after a second or two. It is pretty close and can seem super scary, but as long as you're not turning one way or another too much you should be good. I find that if I place the decopler 3/4ths down on the stack its pretty close to being balanced.