Overheating help

[Keymaster89]

Hi guys!

I have a little problem with heat diffusion along my last craft...

The boosters works well and are capable to get my payload of around 40t to orbit, but halfway the burn of my interstage, the decopuler that hold the payload overheat and explode...

I launch my rocket with 3 TwinBoar boosters with 1 orange tank on top of each (they also have parachute and probe for reenter) the external feeding the internal.

2 of them detach at 45° during gravity turn and works fine, the third middle one fed by the other 2 should bring the whole thing to orbit easily but, the decoupler keep overheating at this point.

The heat propagate from the TwinBoar, through the orange tank, then the probe core and then to the decopuler...

The Twin Boar is maybe an overkill for an interstage, but i use it often as i like really much the sound of it ^^.

So... what should i do to keep the heat away from that decopuler?

Edited May 26, 2015 by Keymaster89

[Xannari Ferrows]

Sounds to me like you're curving them into the air stream, which screams all sorts of problems. Since you're using 3 way symmetry, I don't think there's any configuration to place them so that they don't explode. If you use 2 way symmetry, just place them along the wide axis rather than the long axis.

[Murph]

3x TwinBoar is quite a lot of thrust for 40t payload (I think, without referring to the game to check), but depends how much other stuff there is below the payload stage.

Does the TWR rise above 2.0 at any point prior to the problem? If so, the problem could be going too fast too soon, gaining extra heat from aerodynamic heating. It could equally be getting too horizontal too soon. What altitude are you getting to before failure, and what is your surface speed and angle of prograde above horizon at that point?

If TWR spends much time above 2.0, below about 35km, throttle back to control it (the NASA Shuttle had to do this, it's very realistic), or lose some thrust (e.g. Mainsail core + 2x TwinBoar, instead of 3x TwinBoar).

Do you see any of the visual representations of supersonic effects and/or aerodynamic heating at any point?

[cicatrix]

Someone suggested to attach wing parts on overheating parts, like this:

A makeshift radiator:

[Paul G]

I read on a 1.0.2 tips and advice thread that the orange tank overheats easily and that a lone strut should be placed on it to help with heat absorption.

Paul

[BurningLegion]

Have you considered putting thrust limiters on your Twin Boars to keep TWR from rising too high? I find the sweet spot is about 1.38. It keeps you from losing speed due to air resistance, and slows overheating due to engine heat.

You can also place wings to help radiate heat before it gets to the decoupler. Delta Wings work the closest to best.

[Keymaster89]

Hey guys!

Thanks for the answers! i tryied with the wing-radiator and a less Falcon Punch approach, and this time i get to orbit unharmed!

SOLVED!

[Warzouz]

Sounds to me like you're curving them into the air stream, which screams all sorts of problems. Since you're using 3 way symmetry, I don't think there's any configuration to place them so that they don't explode. If you use 2 way symmetry, just place them along the wide axis rather than the long axis.

I don't get the link between 3-way symmetry and overheating. I use 3 way symmetry and it works perfectly well (with 3 mainsails or 3 mamoth, depending of the payload weight)