Hi Guys, I'm new on this forum, currently studying Aerospace Engineering and am trying to produce the model of a radioisotope thermoelectric generator using numerical methods to solve the heat conduction equation as part of my research. The way it works is that I have a radioisotope source in the middle (let say a cube) generating a thermal power of x W/m3. Different configurations are possible but I want to start as follow. This source is surrounded by a cladding made of a specific alloy to shield it. On top and bottom of this cube there are thermopiles which on one end receive heat from the cladded source and on the other end radiate heat to space. Now, on the sides of this assembly there is a thermal insulator with non zero heat conductivity. My question is the following: Do I need to model this in 2D or 3D to couple the heat losses in the insulator as well as the heat "given" to each distinct thermopile or can I just do simple 1D models in each direction ? In the latter option, should I find the power given by the source to the insulation and substract it to what is given to the thermopile or is this not necessary and I can isolate each case ? Thanks a lot in advance for your help!