If heat is distributed through larger area/volume it will be easier to dissipate, no?
Hi all!
This is me thinking out loud.
Recently I expanded my system with an external rad. Performance is stellar, I love it. But as this is me, I want to push this a little further. I was thinking about adding two more 560 rads to the existing one, putting it all in a nice enclosure ect. Now comes the part I'm not so sure about:
Thinking experiment:
Let's imagine a box with one 120mm rad on one wall, on the opposite wall a 120mm fan. Everything else is air-tight, so that all of the air that gets moved by the fan must go through the one rad. The resulting airflow is what determines the amount of heat dissipated by the rad, and the restrictiveness of the rad has influence on what the airflow is going to be. I imagine this to be somewhat similar to how pumps behave under different head pressures. Less resistance will give better flow.
So if I'd put a 240mm rad in the place of the 120mm, I'd split the airflow in half, BUT I'd have a little more airflow overall because the resistance is exactly half as well, therefore the fan doesn't have to fight as hard. Also, it should be a little less noisy because air is flowing over edges slower.
Now what I'm unsure of:
How does this impact cooling performance. Let's say under given factors, stable ambient, same heat source, same PWM setting on the fan. Which system would result in colder air? What's your guess?
Additionaly and a bit off-topic: Would you put the three rads in series or in parallel? I claim that from a thermal perspective it doesn't have any difference, BUT head pressure on the pump would be 1/3 of one rad instead of 3x one rad. And therefore I'd have better liquid flow with less pump noise.
Title. Ethereal units just lay there dead on the battlefield since TWW1 lol.
Consider that the estimated 10 years of fuel for L2 station-keeping burns is the primary lifetime constraint of the telescope.
Could the energy being dissipated by the Kapton layers ( spaced for different wavelengths to guide these absorbed emissions away from the craft from those different layers) be used to support engine burns for increased fuel efficiency and thus longer science lifespan?
My guess is that there is not enough radiation being emitted from the edges - especially not in any vector-able way useful for navigation.
What will future L2 instrument designs, such as LUVOIR, improve to increase their science lifespan? Are electric Xenon drives too weak to handle the initial L2 insertion even if they'd work for station-keeping?
As a physicist, I have always be fascinated by the power of the fluctuation-dissipation theorem for describing dynamical phenomena (e.g. in NMR or inelastic neutron scattering). All necessary equations are there but I could never figure it out in an intuitive way. It would be great if this question could be addressed in 3Blue1Brown's insightful, yet unintimidating style !
It occurred to me that heat dissipation in the real world goes faster the more heat there is. E.g. if you have two identical objects, but one is at 50 degrees the other at 100 degrees in a room that is 20 degrees, the 100 degree object will lose heat at a faster rate than the object at 50 degrees.
While I don't think that using a "real" equation for heat dissipation would be good (it would be a multiplier on the total heat, which would probably scale in a way that wouldn't be balanced), but it feelslike it would be a nice mechanic if there was a slight increase in the rate at which thermal heat dissipated the more you had total.
An alternate idea would be to allow "venting" of the heat so that the heat you lost above that which gets sent over to the chrono furnaces would just be lost and would not be able to be used for free time skips. This would make it a mechanic which would be better for more active play, but a little less good for more idle play.
My friend dropped something on his computer radiator liquid cooler and bent the fins and then one of the veins that carries the fluid through the radiator and he asked why they were so thin. The goal of the radiator is to dissipate heat, and that got me thinking:
If the radiator tube is a cylinder, is it better to have thicker or thinner walls for heat dissipation over time. Assume a pipe with hot liquid on the inside (100c), copper cylinder walls, and 20c air outside.
***NOTE*** i want to answer this for "over time" as in t=infinity
Here is my thought process. On one hand, thin walls means that the heat goes (liquid -> wall -> air) much sooner, so maybe better dissipation.
On the other hand, when I break it into problems (liquid -> wall) and then (wall -> air), it seems to do this.
Liquid -> wall: Assuming the liquid always stays at 100c, and the wall never loses heat, the wall will reach equilibrium at 100c over time. With thin walls, this happens quicker than thick walls, but eventually it hits equilibrium (100c) theoretically.
Now that the wall temp = liquid temp, then we can add dissipation while changing the wall thickness. Here is where things get tricky. Because this is a cylinder, a thicker wall means more surface area to dissipate heat. We want to talk about steady state (t=1000000 hours) performance, so what happens here? Eventually, if the inner radius is the same for both walls, they intake the same energy and then since the outer walls of the thicker wall is larger, wont it dissipate more heat?
This is confusing me. I think I have the right answer, but I need some help to understand this intuitively.
Thinking diverts to escape the pain of ‘what is’ by solacing explanations:
These are difficult times;
God will take care;
Future will be alright;
People are not cooperative.
It is painful not to be carried away by solaces, by complaining. If you are able to bear this pain, whole energy is here. You begin to see the Truth.
It is this escape, this avoidance that accumulates as stress, pressure.
Work pressure troubles you as you become inclined to the relief offered by entertainments, holidays, intoxications, religious-spiritual ideas, activities. Once noticed, fused state may take over.
Bit of an odd one but the title kinda gives it away
Best way to shift 65w of heat? Passively 👀
Pixel 6 SoC reaches temps of 113°F (45°C)...
> The Pixel 6 Pro in contrast, has quite stark heat spots, with the left side of the phone, near the SoC, getting quite hot at up to 45°C, but at the same time the right side of the device here barely reaches 30-33°C, which is a large temperature gradient and signifies bad heat transfer abilities. https://www.anandtech.com/show/17032/tensor-soc-performance-efficiency
Higher temps significantly decrease the lifespan of the batteries, degrading their capacity faster than normal.
> it was found that when the battery is charged at 113 degrees versus 77 the lifecycle degradation was much more significant at the higher temperature. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4526891/
For comparison, Google had to extend the Pixel 4 warranty for all the battery issues it had (swelling/catastrophic failure/diminished charging capacity, etc), and it didn't run nearly as hot as the Pixel 6 does.
> "Measuring the temperatures of the phones revealed that the Google Pixel 4 XL was running ridiculously hot at a peak external case temperature of 41 C." https://www.notebookcheck.net/The-Google-Pixel-4-XL-is-a-performance-beast-but-it-runs-super-hot.443007.0.html
Building a spotlight using a COB LED and I've got to dissipate 60w (call it 65w) of heat. Don't fancy temps over 80c just to be safe. Again, to be safe I'll say passively cooled, with any airflow an added bonus. I've looked at a 300x145x25mm heatsink but honestly I'm flying blind. Or even just a big aluminium plate 😂 Kinda flying blind as it's not really my thing - just something I said "oh yea I can do that" and now I'm reaping what I've sown
Andrew Huberman Podcast https://open.spotify.com/episode/11UqnJU897Z0Lyu50Uk7Mf?si=5b9ec1bfa28e4c33
Podcast episode summary - https://imgur.com/a/xuSSTkJ
Please read the summary before the following.
Keep in mind the blood vessels in the palms, soles and forehead I mention in the title.
I think a lot of elite runners are going to start reconsidering their form to take advantage of this; or at least it will be tested. In the video below you'll see the best runners in the world have their hands in front and up high by the heart, close to their chest. I think having the hands in front, back of palm facing forward vs more of a chopping arm swing on the sides increases air pressure on the hands and therefore cooling on the hands; as well as the air hitting the chest goes up past the face (over the forehead which sweats a lot and has those specialized blood vessels) and the air hitting the chest moves out to the sides also and hits the palms inside the hands with increased pressure, when the hands are close to the chest.
I'm interested to see what others think.
East African runners hands - https://www.youtube.com/watch?v=5jQwXg4YlhU
See title. There are no electrical components in this cabinet. It's an alcohol-rated, explosion-proof metal cabinet stored indoors in a warehouse.
It seems to me that we should be able to drive a stake through the foundation? He's saying the code requires tying it into the main ground on the electrical panel. I can't imagine why that would be.
I appreciate your thoughts on this.
Edit: /u/jdquinn has explained it well below. I'm leaving this post here for archival purposes.
https://www.freepatentsonline.com/20210303024.pdf
Credit to Mr. Sadly Bradly
