SDK Question Reentry heating/ dynamic pressure

[BruceJohnJennerLawso]

Hello, Im looking to add a destruction sequence to an addon vessel related to ground impacts and/or atmospheric reentry heating. I think I understand the work needed to simulate destroying the ship, creating debris, etc, but I would like to know how to get the hull temperature for a ship. I can see a lot of these functions documented in the Orbiter API reference, but I havent figured out how to actually use them in practice yet.

 

[N_Molson]

It's a relationship between the Dynamic Pressure "GetDynamicPressure()", the Airspeed "GetAirspeedVector(VECTOR3)" and the exposed surface of the vessel (depends of AOA, "GetAOA()"). Maybe the Mach Number too "GetMachNumber()". And, probably, the kind of material exposed is a factor.

But I don't have the formula, and I'd like to know it too. That's thermodynamics.

 

[Quick_Nick]

This might help at least a little: http://orbiter-forum.com/showthread.php?p=228451&postcount=22
It's very difficult to get realistic. Maybe DGIV or XR developers will chime in.

 

[BruceJohnJennerLawso]

It's a relationship between the Dynamic Pressure "GetDynamicPressure()", the Airspeed "GetAirspeedVector(VECTOR3)" and the exposed surface of the vessel (depends of AOA, "GetAOA()"). Maybe the Mach Number too "GetMachNumber()". And, probably, the kind of material exposed is a factor.

But I don't have the formula, and I'd like to know it too. That's thermodynamics.

Youre sure? Maybe its just me, but I think the surface MFD displays external temp in Kelvins, and aerobrake MFD can show a max temp. I appreciate you finding those, but how can I implement them in the code? do I need to call it at say, the start of clbkPrestep/Poststep, if Im creating a destruction sequence, given a DYNP >= a given value? I recognize a lot of these calls from the giant PDF in the SDK directory, but I have no idea how to actually utulize them in code.

 

[N_Molson]

No, external temperature is just the temperature of the ambient air (or vacuum) around your spaceship. It doesn't take friction into account, nor the Sun heat flux (temperature is the same regardless of day/night).

 

[BruceJohnJennerLawso]

No, external temperature is just the temperature of the ambient air (or vacuum) around your spaceship. It doesn't take friction into account, nor the Sun heat flux (temperature is the same regardless of day/night).

Okaaaay :huh:

Im not sure how vacuum itself can have a temperature. (although most spacecraft are never really in a perfect vaccuum)

If youre looking for equations, the link posted above is good, and I think Dansteph mentioned his method on the Arrow Freighter 2012 dev .

But, still, how do I implement those calls in code? do I call them at the start of a cpp section that will use them?

 

[SolarLiner]

After quick search, I found this: http://www.faa.gov/other_visit/avia...ia/Section III.4.1.7 Returning from Space.pdf

I don't read all the document, but there are some formulas to experiment.

 

[icedown]

What is that doing in aeromedical part of the faa site? :hmm:

Lot of good information there though. Any Idea where this came from and where I might find some more like it? It's very seems very thorough and easy to understand.

 

[kamaz]

Any Idea where this came from and where I might find some more like it?

Here is the whole book:

http://www.faa.gov/other_visit/aviation_industry/designees_delegations/designee_types/ame/tutorial/

Most interesting stuff is in section III.4. Basic Concepts of Manned Spacecraft Design