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Why cant I find a chart of materials where each point is a material, and the y axis is thermal conductivity and the x-axis is specific heat capacity
@freemo The style of chart you're looking for is an Ashby chart. With some google-foo, the closest flavor of Ashby chart to what you want I could find publicly available is this:
@freemo The relation between diffusivity (a) and specific heat (Cp) is:
a = k / (rho * Cp)
where k is conductivity, rho is density. So the X axis in this chart is inversely proportional to Cp, but also proportional to k (the y-axis!). The 45 degree dashed lines in the chart are isometric to volumetric specific heat.
This actually answers what I suspected and wanted to answer. I was wondering if the chart would be nice and well ordered (and if so in what way) or just a random jumble with no real relationship... IT is interesting to see that like I suspected there is indeed a close correlation/pattern relating the two across materials.
I was also thinking how some material with really high specific heat capacity and high conductivity would be a very special thing to have, since you can store a lot of energy in it and get that energy out quickly, which in term of energy dynamics is a bit of a holy grail (like in electronics you tend to get one or the other and not both)
@khird Still think of the time it takes to extract heat energy from water, even with its relatively good characteristics. even with huge heat sinks getting the energy out of there is slow.
But more important my thinking here is not at all about practical useful, but rather the fundamental nature of the universe. It is a concept I wrote a lot about and have visited many times. In mathematical terms I am talking about Duals.
So in electronics there is the whole capacitor vs battery compromise, in that you can either have a high capacity and slow access to the energy, or low capacity but quick discharge (fast access). These two relatively constrain themselves through some fundamental law of nature i need to think more on. But it seems duals of it suggest its a fundamental idea in all of nature, so fundamental it fascinates me.
So in this case this seems as a dual expressing that same fundamental relationship, heat capacity is more or less a measure of how much energy i can git in some volume (thermal energy), and thermal conductivity is a measure of how fast you can pull that energy out (or put it in). So it seems like the thermal equivalent of a capacitor vs a battery, and I wondered if it had the same fundamental trade-off (as I suspected it did).
It seems it does...
I need to think more on this, but thats where my head is.