To understand 1D-3D CFD and 3D-1D CFD, we have reviewed the history of attempts at both loose and close coupling of 1D and 3D CFD codes, the motivations of engineers who did it, and the benefits to be gained from these complementary engineering simulation technologies. Not least, because the umbrella term ‘1D/3D’ covers a number of different possible implementations with their own pros and cons.

This paper deals with the use of 3D CFD component simulations embedded inside a 1D thermo-fluid system simulation tool – so-called 3D-1D CFD – and a new workflow conception that we call “Simulation Based Characterization” (SBC) of such system components for added accuracy.