hello all, im modelling a solar collector which is constituted of a wooden box of 1.5 m long, 166mm wide and 70mm high, the box contains an aluminum plate used as an absorber, fixed to it from the top a copper pipe of 1/2 inch diameter. one copper pipe was taken in consideration instead of all the serpentin, this was done with the perspective to gain in number of nodes in the domain and reduce the calculation time. my question is: how processing to make outputs taken into inputs to realise all the serpentin from one pipe, for example: Tout(temperature outlet) of water at the outlet of the pipe is taken into Tin(temperature inlet) of water at the entry of the pipe.

I guess you want to use the periodic BC coupled between inlet and outlet.

the problem is that im using an s2s model, and when i use periodic BC, i have the following message in fluent's window : Error: Error : S2S model does not work with periodic or symmetric boundary condition Error Object: ()

Can you use a different Radiation model then?

well, im trying with the DO model, and i supposed that i have a gray medium in perspective to be closer to the S2S model, i m waiting for results...