Fluid Property Error?
Posted: Thu May 31, 2012 5:47 pm
I have been using you Pressure drop and flow rate calculator for a cooling problem on our hydraulic system (very nice - thanks for your efforts). The cooling system is spec'd at 20 GPM min (chill water temp is about 60 deg F) and is supplied by about 5 ft of 1" copper pipe connected to a 2" header. I wanted to see what the drop (header pressure is about 21 psi) would be across the 5ft of 1"pipe so I plugged in everything and not realizing it I didn't change the units on the viscosity. I came up with a value that I pretty much expected (just under 1 psi drop). Then I noticed that the viscosity units was set to mm2/s. Your chart says that at 10 deg C (close enough) v=1.306 m2/s. If I change the units I get an astronomical value for pressure drop (35,643 psi drop). Mu and Nu seem to correlate but be off by a factor of 1000.
Is this an error or am I not understanding something?
Is this an error or am I not understanding something?