I have some performance data on a particular radiator, and I want to model the system and see if I can't get a simple analytical model to match the data. The problem I'm having is with the air flow rate through the radiator. The only relevant data made available to me is the pressure drop across the radiator. So far, it seems as though this isn't enough.
It's not quite the same as a venturi, because the pressure difference is between the front and back of the radiator, not the front and middle (where the area change occurs). I also considered treating it as an orfice plate, but that introduces another lot of unknowns (coefficient of discharge, ratio of frontal area to solid area, etc.). I also tried just making an assumption about the speed of the air as it hits the radiator, but the model is pretty sensitive to this input, so I don't feel confident making this assumption.
Am I approaching this the wrong way? Is it possible to calculate the mass air flow across a radiator knowing only the pressure drop, exterior dimensions of the radiator and inlet air temperature?