Temperature drop from a cascade aeration process

[FWilson]

I need to calculate the temperature drop in water which starts at one pond at 160 deg F and falls over cascade aeration into a lower pond.. The drop is 8 steps, each 0.8' drop and 2.6' in horizontal length. I know the air temperature and will assume clean water. I need to determine the temperature at the bottom of the cascade, knowing the temperature at the entrance of the cascade. Can't seem to find the right method.

 

[bimr]

Use the formula for an open water tank. Add the vertical drop section to the total horizontal area and you should be close. Subtract the lost BTU's from the energy o f the incoming water.

http://www.engineeringtoolbox.com/heat-loss-open-water-tanks-d_286.html

See the chart on page 18:

http://www.ecw.org/prod/319-2.pdf