Trying to set up a spreadsheet to simulate the Wet Surface Air Coolers such as Niagara manufactures. These are very similar to the coils placed in the flow path in a Cooling Water Tower. I have correlations for counter current flow - Air flow up and deluge water flowing down. I'm looking for some correlations for co-current flow where both the air and deluge water flow down.

Any references or information is appreciated.

Thanks

Bill