thermal conductivity of a liquid cooler
So, given an R5 1600 as the processor, how would I calculate the heat transfer from the processor to a copper water block, then to a liquid (water), then to an aluminum radiator?


Actually calculating these things would be extremely difficult, since it would require you to know things like the distribution of heat on the surface of the processor and the exact properties of things like the thermal interface material.  Instead of calculation from theory, a more common approach is to simply measure the temperature on both sides of a component and the power through it, from which you can calculate the thermal resistance in units of degrees per watt.