Hi Jousefm, I assume you are referring to the natural convection project? not much progress yet.
Have diverted to a structural problem that relates to reported high stress at bolt hole. Dived in to get a feel for the issues. I believe it is caused by the unsupported base of the angle adding bending stresses. Working to confirming or refuting that opinion. Will produce 3 x analysis of fully support 1 with vertical load, 1 with bolt load and 1 with both loads to see how the stress is developed as loads are applied. will repeat for unsupported base. With reference to the natural convection project, current conclusions are it is a bit hit and miss obtaining surface heat transfer values for air to soilid conducting surface. Often surface temperature is not know so requires an estimate (guess) before a valve for the transfer value can be calculated.