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Originally Posted by JayUtah
What I did say is that that process alone could not shed the heat produced by the equipment, the astonauts themselves and the effects of solar energy being absorbed by the spacecraft.
Can you show computations that prove that?
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I believe so. After all it isnt that complicated a problem.I know the alloys the various components were covered with and the level of finish as well as the surface area, so we can calculate fairly accurately the amount of energy over time that would be absorbed by the spacecraft, and likewise we can make fairly accurate calculations as to how much heat can be radiated by radiant conversion by the outside skin of the spacecraft. What we need obviously is more detailed heat budget information where the crafts' internal electronics and other hardware are concerned. I am certainly not thoroughly convinced either way, Jay, since you didn't source your cooling apparatus.
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Originally Posted by JayUtah
Remember, we are talking about a wide spectrum of energy coming from the Sun, reflective material is not sufficient to prevent heating.
Can you describe the "elementary physics" that proves the ineffectiveness of optical surfacing in thermal design? Can you attach actual numbers to the energy, reflection, and resultant heating?
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Actually I have no doubt of the effectiveness polishing a surface has in reflecting certain spectrum of EMR. What I am saying is , it's not just visable light, infared or ultraviolet radiation we are dealing with, it is a wide spectrum of frequencies of EMR and non EMR radiation, all of which can and do cause heating of metallic surfaces when impacting them.Polished surfaces get hot in the bright Sunlight, though aluminum more effectively radiates this heat buildup.The reason for this in the earths atmosphere is simple, because aluminum is such a good conductor of heat, it brings the heat to the surface efficiciently so it can be removed by air molecules passing over it, and by radiative forcing, of course.
In the relative vacuum of space, 'air cooling' is of course not a factor.
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Originally Posted by JayUtah
...there is no escaping that a buildup of heat energy would occur that some process would be required to mitigate.
The basic nature of radiative heat transfer, especially as it relates absorption to emission, says otherwise. Heat does not continue to "build up" indefinitely.
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That's exactly what i said. it would reach a point of equilibrium, eventually. I suspect when we get done with the heat budget calculations on Apollo we will see that temperature will be quite high. First we need a source for your cooling apparatus or this thread is pretty much a waste of time.
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Originally Posted by JayUtah
I would also request he source his information, if possible, so a detailed review of it can be made.
You first.
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I have no sources to quote. I am asking for a simple source of a description of the apparatus you said existed.
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Originally Posted by JayUtah
One thing that has never been explained to me as of yet is why A13 would be cold when we all see a cooling apparatus was required during normal operation.
Because "normal operation" included the energization of electrical equipment, some of whose waste heat was introduced to the cabin. When that operation ceased on Apollo 13 because of the power-conservation measures, the existing heat in the cabin eventually radiated away into space and was not replaced.
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So by your estimation, the heat produced by the electronics was a major part of the heat budget. Interesting.
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Originally Posted by JayUtah
How much heat did the electrical circuits that were lost or deactivated contribute to the overall heat budget of the spacecraft?
In terms of the ECS heat rejection capacity, the substantial majority of the heat load came from electronic equipment. In terms of heating cabin air, the primary source was waste heat tapped from the radiator inlet leg of he primary water-glycol coolant loop. Secondary sources included metabolic heat and direct solar heating of cabin surfaces.
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So you are saying that not only did the spacecrafts electronics need to be cooled, the spacecraft cabin had to be heated by re routing this heat into the cabin. Excuse me if something about that statement seems just a little odd. You are describing a complex cooling system that you never sourced. All I have is your word.
[QUOTE=JayUtah;1041285]
Why would there be excessive heat from properly wired and installed electronics?
Why do you say the heat load from electronic equipment is "excessive?" What, in terms of numbers, is an appropriate heat load from 1960s/1970s electronic equipment of aerospace design? How did you compute or estimate it?
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I can't. Not yet, I don't have crucial information.
That's why I asked you for the information neccessary to do so. I haven't proved anything one way or another , yet.
And I have a feelling you're not going to be able to provide me with the figures. If you can't you can hardly call yourself an expert. You should know approximately at least how much heat was produced by the electronics , I would think this would be a critical consideration in the design process.
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Originally Posted by JayUtah
I know there would be a very minimal amount of heat produced, but it seems irrelevant in the overall heat budget.
How do you know that?
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When electronic circuits produce heat, that is a sign a percentage of the current flowing through the circuit is being converted to heat energy. This would be a complication in the spacecraft design and a totally unneccessary waste of energy. My guess is the circuits were very efficient and produced very little heat. There's no getting around the heat by product of electronic circuits, but it can be reduced to very low levels.
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Originally Posted by JayUtah
What we need to determine...
Shouldn't you have already done that before reaching a conclusion? There is no "we" on that question. You have the burden to prove your statement that the CSM thermal design would not have worked. You have made a number of specific (and often quantitative) claims with no supporting arguments. Until you supply the argument, no one is obliged to do your homework for you.
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I have not reached a conclusion. I am simply representing the opposite side that you are in an open ended debate where neither one of us REALY have the answers. I made it clear the purpose of this thread was for my own question to be answered. It hasn't been.
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Originally Posted by JayUtah
It is my contention that an object in space this near the Sun nomatter how well insulated internally will eventually heat up to an very uncomfortable level...
And it has been explained to you why that contention is not based on physical law. You now have the onus either to reconcile your claims with basic physics or to amend or withdraw them.
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The basic thermodynamic principals involved are not that complicated, but we have a few variables that we do not have values for that we need first to make meaningful conclusions. I have always been undecided on this particular arguement, though I think someone needs to ask hard questions.
One undeniable pattern is that the information I ask of you is never actually provided in a manner that would be helpful to my research.
Sir, with all due respect how do you know? A basic physical law of thermodynamics is that when as more heat energy is produced and absorbed into a system than can be radiated by it in a vacuum ,or removed by other processes, a rise in temperature will occur until a temperature where radiative forcing equals heat being produced and absorbed is reached .
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Originally Posted by JayUtah
In my experience radiators work by circulating a coolant such as propylene glycol anti freeze mixed with water through the object to be cooled, and then through a radiator, which removes heat from the coolant when air passes over it.
The difference between an automotive "radiator" and a real radiator such as used in spacecraft has already been discussed.
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An automotive radiator is not essentially different than the one you describe.The main difference of course is that air moves over the cars radiator and there is no air in space, so your radiator depends on shedding radiant heat and the cooling created by some as of yet unsubtantiated process.
If I understand your description like I think I do, it would work even in a vacuum In fact any experienced backyard mechanic will tell you a full radiator that is leaking coolant will cool BETTER so long as coolant is kept in it, because of the cooling effect of the evaporative process . SO what you describe is a radiator that uses the evaporative process for cooling the radiator, in the vacuum of space, correct?