[thodij]

I am modeling a six-pass (50 tubes per pass) air-cooled condenser to figure out the tube-side flow/vapor quality maldistribution and temperature distribution on the tubes, tube-sheet and header boxes at steady stste. First I need to define the tube-side fluid (coming in at 60% vapor quality). The vapor quality is going to drop until full condensation is achieved in the final passes. I figure that a UDF needs to be written to characterize this condenser fluid. Does anyone have experience writing such a UDF? PLease advise.

We know the "bulk" bahavior of the heat exchanger from use of HTRI software. Unfortunately, HTRI assumes that the incoming header flow is split uniformly across all the first pass tubes.

Any tips/ tricks for writing this condensor fluid UDF will be helpful.

Thanks.