1D heat transfer calculation between two surfaces

[WelshEngineer87]

Hi,
I’m looking to run a simple 1d model to determine the surface temperature of a component that is x distance away From a pipe with and air gap between them, the pipe is covered by thermal insulation.

Up until now I have been using thermal conduction and radiation at the outer surface of the pipe. However I don’t know how to account for radiation across the air gap to work out surface temperature on the other side. I know the emissivities and view factors have an influence. Can I get a reasonable answer without 3D software? I’m assuming convective beat transfer across the air gap is negligible

 

[georgeverghese]

See fig 5-17 for view factors between tube and a plane surface in Perry Chem Engg Handbook 7th ed ( chapter on heat and mass transfer).