After discussing the topic with the whole fxSolver team, G. was wondering how Google will protect its Wireless Routers from the low stratospheric temperatures. The payload of the balloon is limited, therefore they cannot just wrap the router up with a log of thermal-conductive material!
Firstly lets remind that in physics, thermal conductivity is the property of a material to conduct heat. It is evaluated primarily in terms of Fourier's Law for heat conduction.
Heat transfer occurs at a lower rate across materials of low thermal conductivity than across materials of high thermal conductivity. Correspondingly, materials of high thermal conductivity are widely used in heat sink applications and materials of low thermal conductivity are used as thermal insulation. The thermal conductivity of a material may depend on temperature. Also, the reciprocal of thermal conductivity is called thermal resistivity.
Thermal conductivity is actually a tensor, which means it is possible to have different values in different directions.
Thermal Conductivity is calculated with the formula on the left. ΔQ is the heat flow (Joule), Δt the time (seconds), k is the conductivity (W/m*k), A is the surface (m2), ΔT the temperature difference between the ends (K) and Δx is the distance between the ends in meters. Now you can use fxSolver to calculate the thermal resistance of the insulation material!
In the next post, we are going to explore some more formulas that can be applied to this fascinating Google Project. Till then, check out our fxSolver video, and remember to follow or interact with us in our social media pages. You will find links below.