Heatshield protect Thuds?

[Jestersage]

Thought experiment: Assuming a standard fuel tank + capsule, with heatshield at the flat end (so yes, basic standard construction). If I mount 4 Thud thrusters radially, does the heatshield protect them from any heat or not? Some heat? (assuming above 2000k during entry)

Alternatively, what is the best way to find out in terms of re-entry - angle of rentry, etc?

Edited September 30, 2017 by Jestersage

[Spricigo]

1 hour ago, Jestersage said:

Thought experiment

??

If you can keep the Thud inside ot the "protective cone" it will be protected. Given the dimensions I guess it need to be attached pretty high (which may cause CoM issues) 

Also Thuds may be overpowered for the situation. For a small fuel tank and a capsule Twitchs (maybe Spiders) can do the job.

[Jestersage]

9 minutes ago, Spricigo said:

If you can keep the Thud inside ot the "protective cone" it will be protected. Given the dimensions I guess it need to be attached pretty high (which may cause CoM issues) 

Also Thuds may be overpowered for the situation. For a small fuel tank and a capsule Twitchs (maybe Spiders) can do the job.

It was more of a general dimension/shape. Was actually planning more of the SpaceX BFR. I am just designing, hence the "thought experiment"

I thought the heatshield protection is cylinder? Can you elaborate on the "protective cone" - Is it with the point down, or the point pointing up?

Edited September 30, 2017 by Jestersage

[Spricigo]

13 minutes ago, Jestersage said:

I thought the heatshield protection is cylinder? Can you elaborate on the "protective cone" - Is it with the point down, or the point pointing up?

Unfortunately, need to say that I assume it is conical trunk, just a bit larger on the top.

If someone know exactly which shape is the correct one I'd like to know. 

 

[bewing]

It is conical. Just very narrow.

[Jestersage]

1 hour ago, bewing said:

It is conical. Just very narrow.

So it was conical, with the point originate from the heatshield? Or the flat originate from the heatshield?

[bewing]

1 minute ago, Jestersage said:

So it was conical, with the point originate from the heatshield? Or the flat originate from the heatshield?

Flat. But please understand also that some parts (even if they are listed as being the same diameter as the heatshield) can stick out a little further than the heatshield. Such as SciJr's. So you still have to be a little careful.

 

[Foxster]

I have tried a couple of times to determine the  shape of the alleged cone of occlusion behind a heat shield. I tried sticking a load of thermometers at various locations but their readings were meaningless. Then I tried low temperature tolerant parts and turned on the temperature bar display and, again, it failed to show anything useful in terms of the occlusion area outline. 

The only rough feel I got was for a cylinder, though I suppose it could have been a (possibly truncated) steep-sided cone. 

Is there no way to get or calculate the actual shape and length of the occlusion area?

 

[juanml82]

The problem with attaching the Thuds higher up is that their gimbal may cause the exhaust to hit the fuel tank they're attached to and destroy it.

The way I see it you can:

Risk it. Maybe the thuds will survive reentry even if they aren't protected

Have the spare fuel to burn retrograde during reentry to reduce friction

Sacrifice the thuds during reentry

Use the inflatable heat shield (and land on it?)

Edited September 30, 2017 by juanml82

[Palaceviking]

2 hours ago, juanml82 said:

The problem with attaching the Thuds higher up is that their gimbal may cause the exhaust to hit the fuel tank they're attached to and destroy it.

The way I see it you can:

Risk it. Maybe the thuds will survive reentry even if they aren't protected

Have the spare fuel to burn retrograde during reentry to reduce friction

Sacrifice the thuds during reentry

Use the inflatable heat shield (and land on it?)

The inflatable heatshield also detaches. 

[Spricigo]

1 minute ago, Palaceviking said:

3 hours ago, juanml82 said:

Use the inflatable heat shield (and land on it?)

The inflatable heatshield also detaches. 

If light modding is acceptable there is a simple MM patch that allows defrating it also.

[Palaceviking]

2 hours ago, Spricigo said:

If light modding is acceptable there is a simple MM patch that allows defrating it also.

Is that not stock?(I don't keep track of my mods very well) 

[Helmetman]

2 hours ago, Spricigo said:

If light modding is acceptable there is a simple MM patch that allows defrating it also.

@Palaceviking  It's not fully stock, you will need module manager. But it can edit stock files, so if that's mod territory for you? I don't know, kind off...
Wanna go there?
 

Go to opera, chrome, Mozilla, Safari, edge, IE or whatever browser you use. Go to browser settings in whatever respective program and use the "find", "Find page", "Find or press" or "Search" option and type in "Allow Deflating Inflatable Heat Shield" to search for that line of text in the thread page posted above.

"Reveal hidden contents" on the only line found within that thread. Therein lies your answer Spricigo mentioned about. GL 

 

Edited September 30, 2017 by Helmetman

[Spricigo]

18 minutes ago, Palaceviking said:

Is that not stock?(I don't keep track of my mods very well) 

In stock you can: 1. Inflate 2, Jettison

The MM patch allow to deflate (retract) it.

BTW thanks for the link Helmetman.

[juanml82]

4 hours ago, Palaceviking said:

The inflatable heatshield also detaches. 

Yeah, but it can crash into the ship if detached during reenty, depending on the ship's orientation.