Hydraulic diameter of finned tube
Hydraulic diameter of finned tube
(OP)
Hi,
I am trying to determine the hydraulic diameter of a finned tube but I am unsure how work this out. I have attached a diagram showing the tubes and dimensions. The distance between the ends of the fins is 0.5mm. If someone could help with this simple problem that would be great.
I am trying to determine the hydraulic diameter of a finned tube but I am unsure how work this out. I have attached a diagram showing the tubes and dimensions. The distance between the ends of the fins is 0.5mm. If someone could help with this simple problem that would be great.





RE: Hydraulic diameter of finned tube
RE: Hydraulic diameter of finned tube
Regards Brian
RE: Hydraulic diameter of finned tube
There are various "equivalent" diameters used for estimating the Nusselt and the Reynolds number, beside do. Here is one taken from the literature:
Hydraulic equivalent diameter of finned tubes (dHe)
df = external diameter of fin
do = external diameter of bare pipe
p = face-to-face distance between adjacent fins
t = fin thickness
RE: Hydraulic diameter of finned tube
I have found another correlation in the wolverine handbook which can be used to calculate the heat transfer coeffiecient on the air side without the need for working out a hydraulic diameter.
Makes things a bit easier but I will try and work out the h value using the hydraulic diameter to get reynolds number.
RE: Hydraulic diameter of finned tube
Please note that p means the distance betweeen "equal" faces meaning it includes one t.