.FreeFluids.HeatExchangers.BaseClasses.HEXtubes

It is not clear how to calculate the average wall temperature used to introduce corrections in the calculated heat transfer coefficient. I see three possibilities:

· The average temperature of both streams at both ends.

· Split the temperature difference (between the two streams average temperatures) according to the respective heat trasfer resistance of each flow. It seems better, as it is clear that the wall temperature will be closer to the stream with less heat transfer resistance.

· Calculate a wall temperature that will produce the same heat transfer considering the LMTD between this temperature and one of the streams. This is a more complex calculation, and I have not checked that the obtained temperature is the same for both streams.

For now, split the temperature according to the resistance seems the best option.